.375 Cheytac questions

Re: .375 Cheytac questions

Stable in a 9.5 twist, BC 1.247. Wow , that's quite an accomplishment you would think these things would be everywhere.
 
Re: .375 Cheytac questions

I don't think Andre ( Master Diver ) is trying to tease here ... he has sent me a few PM's about what he uses and basically tried to help me. His home range is 700m and he shoots the 355g out of a 1-10.5 with good results. 700m is too close for me to afford the "solid" cost ... but that aside ... his load and wind dope tips make sense ... so I believe his situation is simply one of being shackled by a "distributorship" agreement.

Lots of bullet manufacturer's are like that ... I know of one of the "good guy's" over here having difficulty with Berger ... mainly because others over here who wanted to make more profit were compaining ... so putting Berger in a bit of a fix ... but distributorship agreements can be heavily drafted and heavily enforced.

If you are a "trigger puller" and not just a business guy ... you can tell from experience "who is saying what" in a straight manner ... their loads and data and what they say "stack up".

I think the 414g GSC may need more than a 1-9 but think Augustus gain twist will work ... the B.C. might be a less ... I suspect around "1" ... but then in fairness to GSC his info on the web site gives a banding for B.C. based on the velocity ...

Personally I don't unduly worry about B.C. as advertised ... I can quickly work out the data figures which will work with my software and my barrel and my loads ... I am sure we all do the same ...

However were I to be in Augustus situation from his Cutting Edge results ... I would be tempted to simply stick with what works ...

Sometimes there is enjoyment to be had "developing" and "experimenting" ... sometimes the real pleasure comes from simply "staying on top of the condition" ... YMMV ...
 
Re: .375 Cheytac questions

The other consideration with the CE projectiles is they do expand on game & seem to kill reasonably well with the 4 deer we have shot so far with the 400gr.
They weren't that far away, 415,725,725 & 600 but they weren't going particularly quick either at 2920fps.
I just waiting to sort some reamer/die issues so I can go and shoot some more.
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: PeterWilson</div><div class="ubbcode-body">I don't think Andre ( Master Diver ) is trying to tease here ... he has sent me a few PM's about what he uses and basically tried to help me. His home range is 700m and he shoots the 355g out of a 1-10.5 with good results. 700m is too close for me to afford the "solid" cost ... but that aside ... his load and wind dope tips make sense ... so I believe his situation is simply one of being shackled by a "distributorship" agreement.</div></div>

It is a 800m range
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but the rest is spot on.
The 355 grn SP is for a 1:10 twist but I get great results from my 32" Lawton SS barrel with a 1:10.5 twist.
I have not used the 414 grn SP bullets and do not know if they are stable in a 1:9.5 twist but all other GS bullets always worked great for me and all my customers so why should these not!

Please just try these GS bullets - there are so many that talk about them without having tested them? This I do not undestand! Most of the 375 systems out there cost inbetween $6000-15000 and then people are worried about the cost of 25-50 bullets! WTF
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If you are a rifle builder you can even write them off
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Cheers,

Master Diver
 
Re: .375 Cheytac questions

Agree with master diver, its like bying a dodge viper and complain about gas milage.

Master diver can you send bullete over to me in norway?
 
Re: .375 Cheytac questions

Ragnorok, this is not my first rodeo. I have tested a lot of long for caliber mono metal solid prototypes. Most made pretty little football shaped holes before reaching maximum velocity. The 414 looks very similar to some of the ones I tested. I have already sent 300 USDs across the pond, waited six months for delivery of Lutz Moellers Viking only to have the very first one go end over end.

Many of the other prototypes I tested gave similar results. I know of two people that has fired the 414 and had preceded the tests with much fanfare only to become very quiet after firing only a few. One admitted he suspended testing while he still had several of them. This leaves me in a state of confusion. Why would someone send money across the pond, wait for several months to receive a bullet the is far superior than anything in the world today only to fire a few of them, suspend testing, and start talking to other vendors for alternatives.

I am pretty sure I know the answer to the mystery but I need a hand full of the 414 to confirm or deny my suspicions. Hey SHOOT1760, how about selling me a few of those you had left when you suspended testing.

Some will question why I don't just call Anthony or Gina and order a few. The answer is I conversed with Gina and got the quote of 6USD ea. This included shipping, some sort of customs fee and 3 to 4 month wait time. I would like to have a few of them but not that bad.
 
Re: .375 Cheytac questions

Well it is the same thing for us here in norway and danmark we have to buy a rifle from the us, get a lot of paperwork, wich is really expensive, and just to top it of we need to pay 25% tax on everything including shipping.

Still we buy rifles like 375chaytac and similar. And for now we need to get most of the bullets from U.S. Lukily master diver is selling from danmark, so we can get our hands on the SP series.

And as i understand it should not be difficult to get your hands on the 414 bullets in the U.S as well?

My rifle will be finished soon and im going to order all kinds of diffrent bullets to try out.
And think of the price we need to pay for bullets to get them shipped over . even from US we need to pay like 10% export fee on bullets, and then import papers for projectiles shipping cost and 25% on the top of all the expences.
 
Re: .375 Cheytac questions

Peter,

"Had we stuck with designing bullets to work with the original LRB twist of 1-11.5 for example, then the benefits of gain-twists for those same bullets could have been absorbed better and quicker... Instead what has happened is that alternative bullet providers have gone out to design bullets with "improved BC" capabilities... "...

I can sympathize with your frustration as a consumer, but perhaps this is based largely in the perception that "bullet providers" are up to the task of surmounting, or even understanding the constraints of rifling geometry. ZA is not a "bullet provider" in the common sense. You will not find these publicly available until the infrastructure for barrel distribution is in place. The reason that we have no interest in the 1: 11.5" constant-twist geometry is that it is *functionally* "obsolete".

While your comment on the ES effect upon vertical dispersion is valid, the tandem implication that an improved BC is pointless needs to be revisited. Greater aerodynamic efficiency also mitigates variation in muzzle velocity.

Too much focus is being placed on bullets.

The real progress in ELR is to be found in barrel technology, and when ZA is ready to fully support customers, you will understand how much progress has already been made. Good projectile design is necessary, but not sufficient.
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> The real progress in ELR is to be found in barrel technology, and when ZA is ready to fully support customers, you will understand how much progress has already been made. Good projectile design is necessary, but not sufficient.</div></div> Noel: You're quite correct BUT those of us who have the antiquated constant twist barrels are not going to replace them until we've shot them out. I figure I've got a lot of time for barrel technology to progress a lonnnng way. By the time I'm ready for a new barrel we may well have railguns available for civilian use and projectile design will have changed completely.
 
Re: .375 Cheytac questions

Oh by the way, CE sent me another box of the 425s. I shot a few of them today. This 6.5 barrel loves these bullets, BC seems to be 1.0 at 1000 yds and around .96 at 1770. Does this sound reasonable. I was using only the reticle for the 1000 yd holdover and used both the reticle and clicks for the holdover at 1770. The percentage of deterioration seems to be a little more than the 300 SMK out of the 338/408.
 
Re: .375 Cheytac questions

I have no intrest in shooting the 415 grains bullets.
Im intressed in shooting a lot of different bullets. With 1:10 twist i can shoot the 377 and a lot of other grains, And the difference between the 414 is very little.

I think Im not going to shoot past 2000 meters, and most likly 355 gr will be my obvius choich. And i can order these bullets from master diver in denmark.
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With 1:10 twist i know i can have a really good time and fun with my rifle.
And who in here is going to shoot 3000 meters with great precicion? Brobably no one, sorry for my crappy english
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And what the fuck pal's lets be realistc here. Lests shoot and se what happens insted of this proffesor talk araound here. Lets try differet bullets with differet weights, and twists. So we can share what is working or not.
 
Re: .375 Cheytac questions

Well looks like you have learned enough about the English language to have discovered FORNICATION UNDER CONSENT of the KING. I too am interested in testing and sharing, I have been doing this a long time. Come to think about it I just got through sharing something very few folks on this planet can share. And that sir would be how a 425 gr 375 gr bullet shoots out of a 13-6.5 gain twist barrel. I doubt you can get that info anywhere else.

I need to back track a little here. The will be two places you can get the above mentioned info. I'm about to post on Long Range Hunting.
 
Re: .375 Cheytac questions

Augustus

True enough. I think exactly 2 of those .375 barrels got made. Just like my gain twist 338 (2 got made).

When you finally leave Ok, you can come to the Vegas Desert and we can sling some solids (by then we ought to have some special 338s and maybe 375s to send downrange).

In the mean time, you keep those hounds of yours running. And don't burn the barrel out on that 338 Edge. I plan on getting some trigger time on that beast.

Jeffvn
 
Re: .375 Cheytac questions

Jeff, I've been thinking about getting in the old Dodge and pointing her West. The hounds have been getting a work-out lately. I even had to track down some of my kin last wk, a cousin, same last name. Bayed him in a big farm pond. Oh well just one less place to get a free Thanksgiving dinner.
 
Re: .375 Cheytac questions

Jeff,

There are some unintroduced relatives of those barrels that are overdue for a family gathering.

Las Vegas would be a nice place to hold a reunion.
 
Re: .375 Cheytac questions

I am pretty sure I know the answer to the mystery but I need a hand full of the 414 to confirm or deny my suspicions. Hey SHOOT1760, how about selling me a few of those you had left when you suspended testing.
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Ragnarok</div><div class="ubbcode-body">
I think Im not going to shoot past 2000 meters, and most likly 355 gr will be my obvius choich. And i can order these bullets from master diver in denmark.
smile.gif

</div></div>

I have GSC SP 330, 355 and 414 bullets in stock - for immediate delivery – that is about 2 days for Norway
smile.gif


Cheers,

Master Diver
 
Re: .375 Cheytac questions

Jeff that sounds like fun, I have been puzzled by the deterioration of the BC from 890 yds to 1770. I think the culprit has to do with Inclination angle. I was on a valley floor shooting up on a hill. the inclination angle was 10 degrees. I moved back to 1770 on the flat valley floor but did not change the inclination angle which decreased by around 50 percent to around 5 degrees. This seems to explain the excessive deterioration. I've got a headache thinking about it.
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Ragnarok</div><div class="ubbcode-body">Agree with master diver, its like bying a dodge viper and complain about gas milage.

</div></div>

LOL
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Fair point ... but 800m is a bit close for me to see the "value for money" in shooting solids ... that is perhaps what I should have said ... that and the fact that if I am able to hit what I aim at with repeatable accuracy at a given distance I am more happy, personally, if it is costing me as little as possible.

I guess it is my Scottish ancestry
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Seriously though, by the time you budget for a competitive F Class hobby and travelling to all the comps, some years Internationally, then cover off club shoots, tactical comps and a bit of hunting and shotgun shooting ... it all mounts up.

I really enjoy my long range rifle shooting and built my .375 Cheytac for this and agree you need to buy the right bullets to do the distances ... no worries on that score ... but buying a new barrel to try out new bullets that are often a leap of faith as to whether they will work or not ... that is where I start being careful with my money ... and believe those who are making them ought to put more testing and result information ( R&D ) out in the market place to "underwrite" their product.

The absence of this is why threads like this are very helpful ... and why guys like Augustus and others have my gratitude ... because they are prepared to risk their own money when I am not.

That being said I am happy to share knowledge and experience where I can.
 
Re: .375 Cheytac questions

Master diver, sounds very good.

As soon as my rifle finishes, i will place an order with you. I will work in danmark this summer so i might just drop by your shop.
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Re: .375 Cheytac questions

Leap of faith may be a gross understatement. All the testing, opinions, controversy, hate, discontent, promises, bogus claims etc. has produced so far is the 6.5 barrel/Cutting Edge combination. Although this combination is VERY good, there may be lighter faster bullets out of slower conventional twist that will rival the performance I am seeing.

I have no doubt the 350 gr CE or other similar projectiles will do well without the need for tight gain twist barrels. It is a trade-off, speed or higher BC. I also believe it would be possible to use barrels with very tight standard twists. Although the gain twist I have works great, I am not convinced it is an absolute necessity when firing the solids. Eventually I intend to order a 6 conventional twist barrel to see if my suspicions are correct.

There is one lesson that I have learned very well from this experience, don't take anybodies word for anything, question everything and be EXTREMELY careful where you place your trust.
 
Re: .375 Cheytac questions

"... but buying a new barrel to try out these new bullets that are often a leap of faith as to whether they will work or not... that is where I start being careful with my money... and believe those who are making them ought to put more testing and result information (R&D) out in the market place to "underwrite" their product."...

Peter, you have encapsulated the percieved problem, but conflated two very distinct breeds of "provider". It is true that a debt of gratitude is due to people like Jeff, Frank, Augustus, and others for being willing to trust the barrel specifications recommended by ZA. But for these individuals there would not only been zero progress in the ZA projectile... Cutting Edge would have been consigned to the scrap heap as a low BC extravagance, and GSC would still be beating its chest as the original ELR solid. We now know that these projectiles have very different potentials in the marketplace.

The important point to note however is that both CE, and GSC, were marketed. Therein lies the justification for your complaint, and in the case of GSC, your ire. These folks have not invested adequate R&D prior to product release.

ZA has done no such thing. *You* cannot buy them... yet. When you can, they will come with both "underwriting" *and* the logistic infrastructure to support the product without a six to nine month wait for a barrel that will never optimize the high BC projectile.

Framing the current state of affairs properly will change the complexion of your dilemma substantially.
 
Re: .375 Cheytac questions

Looking at what Agustus has mentioned above in testing the C.E. 425G bullet at 960 yards with a 10 degree up hill inclined angle, which will need less elevation than shooting at 5 degrees up hill inclination for the same distance ( i.e. 960 yards ) ... then dressing back to 1770 yards and shooting the same bullet at 5 degrees up hill inclination ... and observing that the "deterioration" of the B.C. ( or in simple terms the number of come ups required to cover this gap ) to fit in with his elevation dope drops from 1 to .96 ... this is going to be a set of results which you do have to allow for the variable in the inclination angle if you are comparing the bullet's performance in covering off this distance change to other calibre's, such as the .338/.408 shooting the 300 SMK.

If both calibre's are shot in the same place and the same angle variations so these are a "constant" ... then the comparison "stacks up" ... but if the "come ups" seem higher than you expected and the .338/.408 was shot with a constant inclination figure at both distances ... or was shooting at "0" at 1000 yards and say 5% at 1770 ( meaning that it benefitted from needing less elevation at the 1770 distance ) then again these figures need to allow for the inclination ( whether up hill or down hill ) which will assist in needing less elevation than shooting on " the flat ".

What interest's me though is if both rounds were shot in the same place and your data is showing that the 300 SMK is on par with the .425g CE ( albeit going faster than the 425g but we don't know the velocity of that round and that information would be very helpful ) ... then this co-incides with my own experience which has shown that out to a mile and a little beyond the performance of jacketed bullets ( such as in my case the 350g SMK in .375 calibre ) is suprisingly close to that of the more expensive solid bullets ( in my case the few 350g Jamison solids that I had ).

Seemingly for me there was "a zone" where the solid bullets could definately pull ahead ... or saying it another way ... "a zone" where the jacketed bullets performance tapered off ...

But within the distance parameter's of 1000 yards to a mile I felt I could certainly use a jacketed bullet very adequately.

In my case because both bullets were the same weight the solid Jamison needed less elevation at a mile ( and did have a better B.C. ) ... but it is interesting to see that when you go down the route of "lighter and faster" with a jacketed bullet ( i.e. Augustus result's with the 300 SMK )that it is possible to keep "parity" with solid bullet performance.

Whilst not wanting to deviate the thread off the .375 CT calibre ... it would be interesting to me to learn more on the comparison of the 300 SMK .338/.408 and the 425g CE .375. In my case just to see where you discovered that the "zone" of performance started to dip on the jacketed bullet.
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">Peter,

"Had we stuck with designing bullets to work with the original LRB twist of 1-11.5 for example, then the benefits of gain-twists for those same bullets could have been absorbed better and quicker... Instead what has happened is that alternative bullet providers have gone out to design bullets with "improved BC" capabilities... "...

I can sympathize with your frustration as a consumer, but perhaps this is based largely in the perception that "bullet providers" are up to the task of surmounting, or even understanding the constraints of rifling geometry. ZA is not a "bullet provider" in the common sense. You will not find these publicly available until the infrastructure for barrel distribution is in place. The reason that we have no interest in the 1: 11.5" constant-twist geometry is that it is *functionally* "obsolete".

While your comment on the ES effect upon vertical dispersion is valid, the tandem implication that an improved BC is pointless needs to be revisited. Greater aerodynamic efficiency also mitigates variation in muzzle velocity.

Too much focus is being placed on bullets.

The real progress in ELR is to be found in barrel technology, and when ZA is ready to fully support customers, you will understand how much progress has already been made. Good projectile design is necessary, but not sufficient. </div></div>

We have a question on your comment half way thru your second paragraph? What does the barrel infrastructure mean? Does that mean someone is going to buy and stock the barrels or does it mean that until a barrel maker is going to make and do testing of these barrels and bullets? Does it mean the barrels are/will be readily available?

Now on to general comments not directed at anyone.

The bullet makers that are making these special projectiles should be the one making the recommendation on twist rates needed, bore and groove sizes etc....How is the barrel maker suppose to know? Also it seems like the design of these bullets keep changing. Has any design been finalized? We get a fair number of calls on this and there seems to be no real hard data out there.

I don't know of any barrel maker that will make a barrel and guarantee it will shoot this bullet or that bullet. There are more variables besides the barrel that the barrel maker cannot control.


Just curious.

Later, Frank
Bartlein Barrels
 
Re: .375 Cheytac questions

960 yards is not much of a test for a 425 grain 375, and from a Cheytac case, is about 25 grains too heavy to permit consistent internal ballistics.

The additional mass does however compensate for a relatively poor form factor.
 
Re: .375 Cheytac questions

On the issues raised about barrel twists and how or whether gain twist technology or straight twist technology will dominate the performance at ELR ... my own thoughts are that a gain twist assists in mitigating "torque" created in the rifle when the bullet is fired. The gradual build up of spin rather than the instant acceleration from a straight twist assist's in accuracy as the rifle "dips" less and tracks better. This much I do know from shooting 180g Berger's in 7mm in F Class.

Prior to Berger bringing the thicker jacketed 7mm VLD's out ... the thinner jacketed older bullets could also be pushed to higher velocities in a gain twist than in a straight twist.

Again the gradual build up of spin on the gain twist assisted in reducing the stress on the bullet jacket.

With the newer thicker Berger jackets this is not a problem.

So translating these findings to heavier bullets ... I would say that a gain twist is likely to have a better impact on accuracy because the torque on the shot is all the more with a heavier bullet.

For those of us wanting to shoot jacketed bullets it would also assist in the velocity we could push to and in all liklihood would preserve the jacket and the aerodynamic ability for the bullet's concentricity to be "true" for longer shots.

In simple terms the jacket won't be as "beat up" as it would be from a straight twist ... particularly on faster straight twists ... but using the .375 CT calibre as an example ... a 1-11.5 twist is not unduly onerous on the bullet jacket.

When using 1-9 or 1-8.5 twists for 7mm vld's the faster twist rate plays an important part in the torque and the damage to a jacket.

But I would still think a gain twist would be an advantage in shooting any "heavy" jacketed bullet or solid bullet in terms of relieving the issue of torque and how it affects the shot when the bullet is fired. This will be more noticeable still at ELR where the issues will be magnified the further out you go.

For this reason I agree that gain twist technology will play a very noticeable difference in the ability to hold tight groups at say ... a mile ... when the condition variables are constant or when you can be on top of any changes.

Augustus gain twist which runs from 13 to 6.5 is a classic case of how a gradual amount of torque can be reduced compared to starting at 8 or worse 6.

Personally if it were my own money I would'nt be inclined to try a straight twist 6 barrel over a known gain twist ratio which was working well. Not when shooting 400g + bullets. I say that for the above reasons ... but if experimenting and eliminating variables to come to a conclusion was needed ... then fair enough.

Over the years though for me at top end competition ... many of us all say the same ... that no two barrels are alike and that if you get a great one then "that is the year" you need to go for it ... and it may well be that the 13-6.5 is just simply one of those "great" barrels ...

Experience enables you to "tweak" the best out of any barrel but some do have their limits ... in the case of shooting heavy 400g bullets ... the gain twist ratio of 13 to 6.5 makes a whole lot of sense to me though ... and I can see why this particular barrel could be shooting better than the 1-8 twist Augustus has ... solely from the benefits in the twist rate. I think you would get a much cleaner consistant "shot" with those benefit's.
 
Re: .375 Cheytac questions

Frank,

Nobody expects you to be responsible for barrel specifications that are not of your making, and I am personally grateful that you have been willing to produce some unusual geometries... sometimes against your intuitive judgement.

The production ZA barrels are different from anything that you have done. They are produced within the ZA group, and will be distributed only through a handful of designated gunsmiths as finish work.
 
Re: .375 Cheytac questions

Peter, now I really have a headache. If I had not made a bone headed mistake by not accounting for the difference in the inclination angle at the two locations I would not be wondering about the cause of the difference in the rate of deterioration in the two rds. I think the answer is that the 338/408 at 3200 fps is able to mask the deviation better than the slower 375/408 shooting the 425 at 2770 fps. The 338 simply has a flatter trajectory and takes care of dumb asses a little better in this particular case.
 
Re: .375 Cheytac questions

Augustus, I am not sure you made a mistake. Allowing for both rounds being shot at the same locations I think, as you say, that the faster lighter bullet is simply keeping pace with the slower heavier one out to that particular distance.

Because the heavier bullet will retain kinetic energy better and decelerate slower than the lighter bullet then eventually it will pull ahead and need less elevation at a greater distance ... but from your results it looks like up to a mile they are basically very close.

It would be interesting to see how they got on at 1900 to 2000 yards if you are able to go out that far ...

Sort of help getting an understanding of where the "solids" start to dominate ... so that making a discernable decision as to what distances you really need to adopt solids for is a little better understood. Obviously air density plays a huge part ... but that can be factored in ...

Naturally you can shoot solids at any distance you want ... but getting an idea of when it starts to pay radical improvement upon a decent jacketed bullet would be interesting.

My guess is around 1900 yards with that particular combo ... ( until altitude plays a significant part and the air is a lot thinner ).
 
Re: .375 Cheytac questions

Peter,

The difference is simpler than you might think.

With mass held constant, monolithic machined bullets win in all aspects until the sonic transition. This is true even when using a semi-conventional gain twist, although the BC differential does not justify the cost in my opinion.

With the elimination of engraving band drag through use of bore compression, solids achieve ~10% higher BC's than the best jacketed bullets, but the sonic stability remains an issue... only further out.

A PDT cored machined projectile is transition-stable, and not only exceeds jacketed bullets in all metrics... it dominates where mass is held equal.

The velocity/mass balance optimized for a designated range is fun to play with from a physics perspective, but it is not a solids/jacketed contest.
 
Re: .375 Cheytac questions

When I started testing the solids I was looking for BCs above 1.2 with muzzle velocities around 3000 fps. It now appears that is not going to happen with rifles you would want to pack around.

So, the gap between good jacketed bullets and the solids appear less pronounced than first thought. Who knows there may be something around the corner that will change the game.

The CE bullets are fairly conservative in design and I think there is room to increase the BCs. CE philosophy is to produce the highest BC possible w/o getting into all the problems associated with radical designs. They believe that point has been reached.

There are new kids on the block that will continue to push the limits. I can't wait to see what pops up in the next couple of yrs.
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Augustus</div><div class="ubbcode-body">Peter, now I really have a headache. If I had not made a bone headed mistake by not accounting for the difference in the inclination angle at the two locations I would not be wondering about the cause of the difference in the rate of deterioration in the two rds. I think the answer is that the 338/408 at 3200 fps is able to mask the deviation better than the slower 375/408 shooting the 425 at 2770 fps. The 338 simply has a flatter trajectory and takes care of dumb asses a little better in this particular case. </div></div>

Augustus, I'm looking forward to you getting those 425s humming along, that will probably change the BC a little.
I asked CE to make the 425s in February as I could see from my testing of the 350,375 & 400s that it would be worth the "leap of faith".
My testing has shown that they are nearly "ballistic triplets" by that I mean that as the weight/BC increases the speed decreases proportionately, with the heavier projectles just edging ahead & the 425 seems to do a little better than the 400 in this regard.
My exit twist is 7.8 & seems to be working fine so far but I haven't fired enough 425s at distance to know precisely.
My rifle liked the 400s & have shot sub moa out to 1700.
I'm currently waiting on another reamer to sort out my die issues & haven't fired my 375 for a while now.
As is is smaller than the Cheytac case I'm very happy with performance so far with the 400s leaving at 2920 & the 425s leaving at 2850-60.
We have been waiting reasonable paitently for more Bartlein barrels that were due around last X-mas to chamber with a Cheytac case to get more performance, apparently this issue may be getting close to being sorted......
Once they finally show up we should be able to realise the potential of the CE projectiles
cool.gif
 
Re: .375 Cheytac questions

"The gap between good jacketed bullets and the solids appears less pronounced than first thought."...

The 1.2 BC mark was always arbitrary, and probably an artifact of early field estimates from testing of the 420 grain ZA (notoriously inaccurate). That said, the 150-200 fps advantage that a solid has by virtue of a better mechanical interface compounds with a more efficient form to justify their use at present... not two years from now.

Kiwi, you cannot drive the 400 grain CE solids past 3,000 fps?
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">
Kiwi, you cannot drive the CE solids past 3,000 fps? </div></div>

Yep 350s just over 3100, 375 just over 3000, 400 just over 2900 & 425 well over 2800.

It is smaller than a Cheytac case I'm using 112-116 grains to acheive those speeds
smile.gif
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">Is this a case of your own design? </div></div>

Yes, similar to others using a conventional case.
 
Re: .375 Cheytac questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">I think that I know what you did, and why you did it. If so, what you lost in case volume was compensated by a lower ES? </div></div>

I used a standard throat length.

The CE bullet design is good like that.

Here is a picture etc of the rifle, & performance of the 400 projectile, all be it quite close.

http://www.nzhuntingandshooting.co.nz/f17/ashlees-fist-red-stag-1417/
 
Re: .375 Cheytac questions

I happen to have the 35 set up. It won't take but an hr or so to see how fast the 425 will go with 869. Be back shortly... Stay tuned the drama continues.
 
Re: .375 Cheytac questions

Augustus said:
I happen to have the 35 set up. It won't take but an hr or so to see how fast the 425 will go with 869. Be back shortly... Stay tuned the drama continues. [/quo

Great stuff be keen to see what 869 will give you with jamison brass with the 425s
 
Re: .375 Cheytac questions

Ok,
145 gr 869-- 2950 and 2966 accuracy .6 Moa at 100 yds. I used the same pc of brass for both rds. First firing extracted with one finger, second firing was a little tighter but GTG.

147 gr of 869 3001 fps, this Rd cut one of the other two rds. Extraction was sticky on a pc of virgin brass. DONT DO THIS FOLKS. US 869 has a nasty habit of getting fed up all of a sudden.

140 gr. Of 50BMG--- 2830 and 2826 fps on two rds. .5 min. Accuracy for the two rds. This load is 100 percent load density with the 425 seated to the band kissing the case mouth. Extracted with no resistance on both rds using the same pc of brass.