Using Bullets That Are Not Sensitive To Seating Depth

[Glassaholic]

Listening to The Everyday Sniper Podcast with Frank and Mike they were talking in one of the episodes about shorter barrels and Frank was mentioning lighter bullets with high BC's that you can still get good speed out of. Frank mentioned he likes the Scenar's because they are not as jump sensitive as Bergers. Call me a lazy reloader but I have avoided Berger by and large due to price and their "sensitivity" to seating depth. Nosler has their new RDF bullets and Hornady has their new ELD series, my preference would be to load to magazine length for both 7 RSAUM and 6.5 Creedmoor (using Alpha mags) and I'm curious what the experience has been with RDF's and ELD's when it comes to loading to magazine length and accuracy instead of going through the process of 500ths off the lands 600ths off the lands and so forth. I understand for many of you reloading is an art form and you have perfected your brush strokes, but I have not bought into that yet and curious if there are others who load to magazine length or just under with these new bullets and what your experience has been. For some, squeezing every teensy bit of accuracy out of their loads is the objective and getting 1/4 to 3/8 MOA is the goal, but for me, if I get 1/2 MOA out of my loads well, I am okay with that, I have played with different seating depths from magazine length and have seen little in accuracy gains in doing so. Load development is pain enough without having to deal with seating off the lands, but am I being ignorant with my approach or is there validity in using bullets that are less sensitive to jump and loading to magazine length or within close proximity thereof?

By the way, for load development I have been using Dan Newberry's Optimal Change Weight method for a number of years now with good success, so it's not like I'm just throwing powder and seating my bullets willy nilly, I do have a process and I am curious if there are bullet designs that tend to provide greater accuracy using this methodology.

 

[kthomas]

Myself, and lots of others, have had issues with getting the RDF's to shoot consistently. A lot of unexplained fliers, probably due to inconsistencies from bullet to bullet. I wish that these bullets would work, as they have great BC, great price and I have a thousand of them. These will now be barricade practice bullets.

Berger hybrids aren't that jump sensitive, not that I'm aware of. From everything that I have read and experienced, they like 0.010" - 0.020" jump.

I'm swapping from RDF's to Berger Hybrids, as I know I'm getting a quality and consistent product from Berger. There is a reason why a lot of people across multiple precision rifle disciplines use them, and that is because they just plain work. I haven't reloaded any ELD bullets, but they are certainly another bullet that I would consider.

 

[lash]

I'm another of those lazy reloaders I guess. I still shoot the 136g Scenars and have been for years. They just work in everything loaded to mag length and tuning is easy.

 

[MarinePMI]

I shoot the RDF's as well. I haven't noticed any fliers, but have read some do.

Shrug...when shooting 1-2 MOA targets I'm of the belief that it really doesn't matter getting the uber accuracy by chasing seating depth. Will that lack of attention cause me to miss a target? Maybe. But in my mind, most misses at range are due to incorrect wind calls. If a bullet allows easier wind calls due to a higher BC (less wind drift), but doesn't shoot as tightly as another less efficient bullet, then it's a wash in my mind, with it leaning favor toward the more efficient bullet being "better".

I know others here will disagree, but that is my thinking on it. If I'm going to miss at long range, it's usually a bad wind call. Anything that gives me an advantage in calling wind (in my mind) trumps that .2" gain in accuracy in a grouping.

 

[Shortbus6588]

I suggest Hornady ELD-M, I've used there in several calibers and they have been insensitive to seating depth and jump. They have a rather large bearing surface which helps with that and a very good b/c number

 

[kthomas]

I shoot the RDF's as well. I haven't noticed any fliers, but have read some do.

Shrug...when shooting 1-2 MOA targets I'm of the belief that it really doesn't matter getting the uber accuracy by chasing seating depth. Will that lack of attention cause me to miss a target? Maybe. But in my mind, most misses at range are due to incorrect wind calls. If a bullet allows easier wind calls due to a higher BC (less wind drift), but doesn't shoot as tightly as another less efficient bullet, then it's a wash in my mind, with it leaning favor toward the more efficient bullet being "better".

I know others here will disagree, but that is my thinking on it. If I'm going to miss at long range, it's usually a bad wind call. Anything that gives me an advantage in calling wind (in my mind) trumps that .2" gain in accuracy in a grouping.

I agree, I would settle for 1/2 MOA accuracy. Wind is much more important than shrinking groups to 0.25 MOA or less - and people lose sight of that. 0.25 MOA groups do not win PRS matches. Strong wind calling skills and the ability to quickly build a steady barricade position wins PRS matches.

However, with the RDF's, I couldn't get the groups below 1 MOA. They were ~1.5 MOA groups, which is unacceptable.

 

[spife7980]

My experience with the 500 rounds of the 70 rdf was that everything was a flier at all powder charges and all seating depths. My 105 rdfs are much more responsive to changes in depth and put together some solid groups.

Im goin to try the elds next but I’ve really been thinking about a matchking. Sure the 80 matchking has a lower bc compared to the eld but if it’s that much easier to get shooting great the juice might not be worth the squeeze for the extra half inch of drift difference.

 

[MarinePMI]

Just to clarify/add, I couldn't get the 70gr RDF's to shoot either. The 140gr 6.5's however, have given me no problems.

 

[Hondo64d]

Listening to The Everyday Sniper Podcast with Frank and Mike they were talking in one of the episodes about shorter barrels and Frank was mentioning lighter bullets with high BC's that you can still get good speed out of. Frank mentioned he likes the Scenar's because they are not as jump sensitive as Bergers. Call me a lazy reloader but I have avoided Berger by and large due to price and their "sensitivity" to seating depth. Nosler has their new RDF bullets and Hornady has their new ELD series, my preference would be to load to magazine length for both 7 RSAUM and 6.5 Creedmoor (using Alpha mags) and I'm curious what the experience has been with RDF's and ELD's when it comes to loading to magazine length and accuracy instead of going through the process of 500ths off the lands 600ths off the lands and so forth. I understand for many of you reloading is an art form and you have perfected your brush strokes, but I have not bought into that yet and curious if there are others who load to magazine length or just under with these new bullets and what your experience has been. For some, squeezing every teensy bit of accuracy out of their loads is the objective and getting 1/4 to 3/8 MOA is the goal, but for me, if I get 1/2 MOA out of my loads well, I am okay with that, I have played with different seating depths from magazine length and have seen little in accuracy gains in doing so. Load development is pain enough without having to deal with seating off the lands, but am I being ignorant with my approach or is there validity in using bullets that are less sensitive to jump and loading to magazine length or within close proximity thereof?

By the way, for load development I have been using Dan Newberry's Optimal Change Weight method for a number of years now with good success, so it's not like I'm just throwing powder and seating my bullets willy nilly, I do have a process and I am curious if there are bullet designs that tend to provide greater accuracy using this methodology.

Berger classic hunters have been extremely forgiving in regards to seating depth and have a decent BC. Berger hybrids have worked well for me too.

185gr Classic Hunters from my Criterion .308 barrel. Five shots.

John

 

[Marksman10x]

Berger VLD's are seating depth sensitive, but their Hybrid and Classic Hunter lines are not at all sensitive and shoot very well at magazine length.

 

[Glassaholic]

Thank you all for responses so far. I thought I had read even the Berger Hybrids have had issues, but maybe it’s more about eking the last 1/8 moa out of them vs erratic behavior at magazine length. Sounds like a mixed bag with the RDF’s but good results with ELD’s so maybe I’ll stick with Hornady. I also bought a case (500) of Norma Golden Target 130’s that Prime uses in their loads with “claimed” high BC numbers so curious how this will work out. What I’m trying to avoid is a box of this and a box of that, trying to settle on a reasonably priced bullet and then buy in bulk but so far I’ve been pretty happy with Hornady Match and Prime ammo I haven’t even reloaded my 6.5 CM yet which has given me time to consider which bullet to choose.

 

[Glassaholic]

Thanks John, the hunters I can get in bulk for a pretty good price so I might take a look at those again

 

[OzTRG]

Late to the conversation and I reload so I can shoot, the reloading game in and of itself is not something I relish. However following the Berger reloading manual with 4 suggested seating depths to test post OCW I have not found it difficult to get .3 to .4 MOA out of berger 210 VLDs in my 300WM or the berger 130gn hybrids from my 260 rem. Even with throat erosion after a couple of thousand rounds I have not noticed a sensitivity to seating depth. My 2 cents worth

 

[dannySH]

I'm one of the guys with bad luck with the 140 gr RDFs. Tested them in two rifles with many powders between 0.01"- 0.08" and the only thing I got were fliers at any time. 140 gr ELD-M is another story, sub 1/2MOA on both rifles at 0.02" off the lands

 

[Hondo64d]

My barrel hated the RDFs too. Couldnt get any combination of charge or seating depth to group well. Loves the 140gr hybrids though, shooting in the .3s and .4s.

John

 

[Kopfjager1]

I bought 308 178 ELD-Ms thinking (hoping) they would work, I thought I had a load developed with single digit SD/ES, loaded up 25 to confirm all of them would be a wash. Repeated for each accuracy node I found, all them were erratic at best. Switched to 175 RDFs, went back to the first accuracy node, which was 43.1 to 43.9 gr of Varget, and just good SD/ES with <0.5 MOA between 5, 5 round groups.

The measurements I was getting with the ELD-Ms were all over, weight, bearing surface, length. The RDFs were way more consistent besides OAL length, bearing surface and base to ogive were all +/- 0.0005".

However my 6.5 CM shoots the 140 ELD-Ms great at the entire charge weight spectrum. It was rather easy developing a load, and messing with seating depth yielded the same results both in velocity and accuracy, SD/ES fluxuated a little bit, but not enough to be certain on a particular seating depth.

 

[kansas]

I shot 139 Scenars in all of my .260s and all of them loved them and didn't care how they were seated. I've since changed to a 6mm and have bought 110 SMKs and 105 Hybrids to try. Just need the weather to cooperate a little. IF the Bergers don't shoot well then I'll be back to the Scenars in this caliber too.

 

[918v]

If you’re blaming poor performance on jump sensitivity then your load or case prep needs altering.

 

[RyanM]

I think there are types of seating depth sensitivity.

1) Your load being +/- a couple thou and still being a great load
2) Your load being able to shoot well at 50 thou jump to a jam.

I am not really sure the second type actually exists - I at least have not encountered it. I was being lazy and working up a load for my 223 and left the seating die as is. I measured post charging and found I was jumping .04 or .05. The load was not great but once I get the bullet back to a more sane .01 or .02 jump I am sure it will be good to go.

For what it is worth I pretty much only shoot Berger Hybrids or non-vld Bergers. I have found that I can pretty much always get them 1/2 minute with very little work.

 

[DynamicAccuracy]

I shoot 142 smk in my 6.5x47 and it shot under 1/2 moa at 300 yards from .005-.050 of the lands.

 

[DynamicAccuracy]

Ive find matchkings to be less sensitive to seating depth.

 

[Glassaholic]

If you’re blaming poor performance on jump sensitivity then your load or case prep needs altering.

Not blaming poor performance on anything, just asking the community for advice on bullets that have shown to be more forgiving when it comes to seating depth because I'd rather load based off magazine length than worry about how far off the lands I am. I called my own self lazy in this regard because diligent reloaders often go through painstaking processes to get the uttermost accuracy out of their loads (I know, I used to be that, but I'm not as anal as I used to be). That being said, I have had good luck so far with seating based off the mag length and using the OCW method to build up load development.

Based off the responses so far it seems quite a few have not had good luck with the Nosler RDF's (but a few have), while some have had good luck with the Hornady ELD's (but some haven't) and most have had good luck with Berger's and everyone has had good luck with the Scenar's. My other driving factor is cost, the Berger and Lapua's are the most expensive by over 10 cents per bullet vs. the Hornady and Nosler which equates to $100 per 1000 bullets. Okay, so I'm lazy and cheap But seriously, if I can work up a 1/2 moa load using Nosler or Hornady and save $100 per 1000 then why not? Sounds like the 6.5mm and 7mm bullets have been more forgiving in general than the 308 bullets so I think its worth trying out a box of the lower cost RDF's and ELD's for my 6.5 and maybe even for my 7mm.

 

[kthomas]

If you really don't want to try the Berger's, I would start with the ELD's before going to the RDF's. No point in creating a headache by trying to avoid a headache.

Seating tests are easy and simple to do, easier than trying a bunch of different bullets at mag length. I feel like you are causing yourself more headaches then you are preventing.

 

[Glassaholic]

If you really don't want to try the Berger's, I would start with the ELD's before going to the RDF's. No point in creating a headache by trying to avoid a headache.

This was my thought as well. Price is right and they seem to get more praise than some others.

Seating tests are easy and simple to do, easier than trying a bunch of different bullets at mag length. I feel like you are causing yourself more headaches then you are preventing.

I suppose I'm trying to get away from a "bunch of bullets at mag length" which is why I post the question on which bullets are the least sensitive to seating depth so I don't have to test a bunch of bullets. Sounds like I keep coming back to the Hornady ELD-M's so I might as well start there.

Thanks again everyone.

 

[MachoKing]

I don't have any experience with the RDF but the ELD's and Berger Classic Hunter have been incredibly easy to tune for me.

 

[918v]

Not blaming poor performance on anything, just asking the community for advice on bullets that have shown to be more forgiving when it comes to seating depth because I'd rather load based off magazine length than worry about how far off the lands I am. I called my own self lazy in this regard because diligent reloaders often go through painstaking processes to get the uttermost accuracy out of their loads (I know, I used to be that, but I'm not as anal as I used to be). That being said, I have had good luck so far with seating based off the mag length and using the OCW method to build up load development.

Based off the responses so far it seems quite a few have not had good luck with the Nosler RDF's (but a few have), while some have had good luck with the Hornady ELD's (but some haven't) and most have had good luck with Berger's and everyone has had good luck with the Scenar's. My other driving factor is cost, the Berger and Lapua's are the most expensive by over 10 cents per bullet vs. the Hornady and Nosler which equates to $100 per 1000 bullets. Okay, so I'm lazy and cheap But seriously, if I can work up a 1/2 moa load using Nosler or Hornady and save $100 per 1000 then why not? Sounds like the 6.5mm and 7mm bullets have been more forgiving in general than the 308 bullets so I think its worth trying out a box of the lower cost RDF's and ELD's for my 6.5 and maybe even for my 7mm.

There is no such thing as “forgiving” in the realm of bullet jump. It is what it is- bullet jumps to the rifling, but how much is not important. What matters is the bullet starting position relative to the muzzle. For example, take two different lots of .308” 175SMK, one having .025” shorter bearing surface than the other. Using the same seater die setting you’ll get the same OAL, but one will have .025” more jump to the lands. Most people will make the mistake of adjusting the OAL of the bullet with the shorter bearing surface to match the jump of the bullet with the longer bearing surface. This will increase the OAL and change the load. On the other hand, leaving things alone preserves OAL and accuracy because what matters is the bullet’s starting position, not how much it jumps.

It doesn’t matter if it’s a tangent, secant, or SWC.

 

[918v]

Maybe you should be looking into the forgiving nature of the load itself. Take the old 168SMK FGMM load from 20 years ago, 43.5grs of 4064. That load shoots great from 2.790” to 2.810” OAL. It is not that 168SMK is forgiving, but the particular powder charge is.

 

[Glassaholic]

There is no such thing as “forgiving” in the realm of bullet jump. It is what it is- bullet jumps to the rifling, but how much is not important. What matters is the bullet starting position relative to the muzzle. For example, take two different lots of .308” 175SMK, one having .025” shorter bearing surface than the other. Using the same seater die setting you’ll get the same OAL, but one will have .025” more jump to the lands. Most people will make the mistake of adjusting the OAL of the bullet with the shorter bearing surface to match the jump of the bullet with the longer bearing surface. This will increase the OAL and change the load. On the other hand, leaving things alone preserves OAL and accuracy because what matters is the bullet’s starting position, not how much it jumps.

It doesn’t matter if it’s a tangent, secant, or SWC.

Here me out 918v, I understand what you are saying (at least I think I do) with regard to the ogive and OAL and how different lots may have different "jump" to the lands, but you're saying that doesn't matter as long as the bullet is seated to the same length? Taking this into account, how will that impact loading to magazine length? It almost sounds like you're saying my methodology of loading to magazine length will work out just as well in this scenario or am I misunderstanding?

 

[Glassaholic]

Maybe you should be looking into the forgiving nature of the load itself. Take the old 168SMK FGMM load from 20 years ago, 43.5grs of 4064. That load shoots great from 2.790” to 2.810” OAL. It is not that 168SMK is forgiving, but the particular powder charge is.

So are you saying that seating depth really doesn’t have much of a factor as long as you have the optimal charge weight? If this is the case then one should be able to make an accurate load regardless of the bullet being used? But if that were the case then why so much struggle with various bullets as mentioned in multiple posts above? Just trying to get a better understanding is all.

 

[918v]

Seating depth is a critical factor as far as the bullet starting position relative to the muzzle. But it’s not the ogjive that’s critical. It’s the base. The base exits the muzzle last. The base/muzzle relationship is what controls accuracy. You need both, an ocw and an optimum oal, but that oal is not determined by the ogjive which varies from lot to lot.

 

[918v]

Here me out 918v, I understand what you are saying (at least I think I do) with regard to the ogive and OAL and how different lots may have different "jump" to the lands, but you're saying that doesn't matter as long as the bullet is seated to the same length? Taking this into account, how will that impact loading to magazine length? It almost sounds like you're saying my methodology of loading to magazine length will work out just as well in this scenario or am I misunderstanding?

Yes, seated to the same optimum length as far as the base of the projectile is concerned. Whether that oal fits in your magazine is another issue. That will depend on your particular firearm barrel length, freebore, etc. For example, it might be that your optimum oal is 2.850” but you have a short freebore and you’re .020” in the lands at that oal. Obviously you can’t use it. You have to find another oal, another ocw. On the other hand, if your bullet touches the lands at 2.925”, but your optimum oal is 2.850” , don’t sweat the .075” of jump. My TRG-22 shoots like a laser while jumping bullets that much.

Bottom line, both ocw and oal are important, but the amount of jump to the lands is not.

 

[lte82]

Yes, seated to the same optimum length as far as the base of the projectile is concerned. Whether that oal fits in your magazine is another issue. That will depend on your particular firearm barrel length, freebore, etc. For example, it might be that your optimum oal is 2.850” but you have a short freebore and you’re .020” in the lands at that oal. Obviously you can’t use it. You have to find another oal, another ocw. On the other hand, if your bullet touches the lands at 2.925”, but your optimum oal is 2.850” , don’t sweat the .075” of jump. My TRG-22 shoots like a laser while jumping bullets that much.

Bottom line, both ocw and oal are important, but the amount of jump to the lands is not.

So why not cut super long freebore into everything if jump doesn't matter? I guess everyone is doing it wrong?

 

[Glassaholic]

Seating depth is a critical factor as far as the bullet starting position relative to the muzzle. But it’s not the ogjive that’s critical. It’s the base. The base exits the muzzle last. The base/muzzle relationship is what controls accuracy. You need both, an ocw and an optimum oal, but that oal is not determined by the ogjive which varies from lot to lot.

Thank you 918v, you have me thinking more about this and understanding new concepts. So it's not so much the jump to the lands and trying to figure out you need this thousandths or this hundredths off the lands, it's more about the distance between the base of the bullet and the tip of the rifle? It almost sounds like harmonics plays a role here as well, and really you're trying to measure or adjust for the right harmonics vs. trying to get the perfect jump. But then you mention the freebore and how different reamers can yield different freebores and yet that doesn't have an effect on that seating depth, obviously you don't want a short freebore and long OAL which will jamb into the lands, but you're saying that whether it's 15 thousandths off the lands or 2 hundredths isn't going to matter as much as the distance from the base of the bullet to the tip of the crown. If this is truly the case, then my proposed methodology of seating to magazine length getting optimum OCW off that, and then playing around with different thousandths off the magazine length should yield similar results as if I was measuring off the lands, yes?

 

[918v]

So why not cut super long freebore into everything if jump doesn't matter? I guess everyone is doing it wrong?

Who is everyone? How close a bullet is to the rifling affects pressure. It affects velocity. There are chambers with very little freebore and others with a lot. There isn’t a lot of agreement how much freebore is ideal.

 

[918v]

Thank you 918v, you have me thinking more about this and understanding new concepts. So it's not so much the jump to the lands and trying to figure out you need this thousandths or this hundredths off the lands, it's more about the distance between the base of the bullet and the tip of the rifle? It almost sounds like harmonics plays a role here as well, and really you're trying to measure or adjust for the right harmonics vs. trying to get the perfect jump. But then you mention the freebore and how different reamers can yield different freebores and yet that doesn't have an effect on that seating depth, obviously you don't want a short freebore and long OAL which will jamb into the lands, but you're saying that whether it's 15 thousandths off the lands or 2 hundredths isn't going to matter as much as the distance from the base of the bullet to the tip of the crown. If this is truly the case, then my proposed methodology of seating to magazine length getting optimum OCW off that, and then playing around with different thousandths off the magazine length should yield similar results as if I was measuring off the lands, yes?

Yes. Except you’re not guaranteed to have your cake and eat it too, if we define that as max velocity and forgiving tolerances.

 

[918v]

My TRG magazine accepts OAL as long as 2.950” and my bullet hits the lands at 2.900”. My optimum oal is 2.830”. I have a lot of room to play. Some people are in the lands at 2.830” with this bullet, not a lot of room.

 

[lte82]

Who is everyone? How close a bullet is to the rifling affects pressure. It affects velocity. There are chambers with very little freebore and others with a lot. There isn’t a lot of agreement how much freebore is ideal.

Sure there is. It's ideal to seat the bullet shank above the potential donut area for a number of reasons. Then you can come up with a minimum freebore for whatever bullet you shoot. Why would nearly every gunsmith spec their own reamer. Or own a 0 freebore reamer and a separate throating reamer. Why not just set all of them the same to accommodate the worst case scenario? Why does Berger have a write up explaining how to test how close your bullets like to be to the lands. Why are hybrids billed as "jump sensitive" if jump has zero effect. The entire industry refers to jump to the lands. Bullet base to muzzle length is not something I've ever used, read about, or heard on the firing line...

 

[steve123]

I could mention some things.

Sometimes regular VLD's, like Bergers, can be a real pain in a hot cartridge like 6x47l, redo load/depth every 400 rounds or so. I learned the hard way. In my 223 the 70 vld has worked fine for the last 4-5 years and I haven't changed anything.

Switching to the 115 DTACS in the 6x47l was a great decision. Only once in the barrels life, about .75% of it's life did I have to redo the load and depth.

Changed to the Berger hybrid, man those are just great bullets and in three different cartridges I have gotten fantastic results in every way, they are expensive though. I did a ladder test and didn't feel I needed to change the SWAG depth at all.

Read too many bad reports about the RDF to consider trying it.

I did change over to the 225 ELDM, mostly because they are cheaper. I have no complaints, they shot extremely well at ELR distances, as good or better than the 230 hybrids.

For cheap and having fun on steel, I'd try the Hornady HPBT's. Slight loss in BC but at normal distances the difference won't hardly be noticed.

 

[Glassaholic]

For cheap and having fun on steel, I'd try the Hornady HPBT's. Slight loss in BC but at normal distances the difference won't hardly be noticed.

Was thinking about this as well, they are about 5 cents less per bullet or $50 per 1000, but it seems the ELD's have the better rep for loads. When I shoot the Hornady Match 140 ELD-M ammo it definitely groups better from my rifles vs. the Hornady American Gunner with 140 HPBT loads, but some of that could be other variables and the machines which load their Match ammo vs. the "cheap" American Gunner ammo.

 

[918v]

Sure there is. It's ideal to seat the bullet shank above the potential donut area for a number of reasons. Then you can come up with a minimum freebore for whatever bullet you shoot. Why would nearly every gunsmith spec their own reamer. Or own a 0 freebore reamer and a separate throating reamer. Why not just set all of them the same to accommodate the worst case scenario? Why does Berger have a write up explaining how to test how close your bullets like to be to the lands. Why are hybrids billed as "jump sensitive" if jump has zero effect. The entire industry refers to jump to the lands. Bullet base to muzzle length is not something I've ever used, read about, or heard on the firing line...

FYI, if you map out charge weight vs OAL and locate the center of the node, and if the node is broad enough to tolerate plus/minus a few tenths of a grain and plus/minus a few thousandths of length, then the amount of jump to the lands becomes irrelevant.

I once called Sierra and complained that my new lot of 175SMK had a .040” longer BTO but the projectile length was similar. The guy laughed at me and explained they take “great care” to make sure every lot of their bullets seats to the same OAL using the same die setting. I knew this to be true, but did not understand what he meant. I continued to chase lands and grew increasingly frustrated at the inconsistency. I switched to Hornady because they were more consistent in terms of BTO from lot to lot. I shot them for a long time.

Then one day I looked into the various FGMM configurations over the years and read they used to load 43.5grs under the 168SMK. I duplicated the load. I did not work it up. I just slapped it together using 2.8” OAL. It shot 3/8”. I adjusted the OAL in hopes of shrinking it further and found it maintained accuracy over a .020” OAL range. Then I tried it with a second lot and a third lot of bullets, each having different BTO lengths and got the same results.

I found that no matter which lot I use, as long as I maintain the same die setting/OAL the rifle shoots like a laser despite there being a huge disparity in jump length. This goes for both the 168 and 175SMK. Huge disparity in jump length does not affect accuracy as long as the OAL remains the same. This tells me the base of the projectile relative to the muzzle trumps ogjive to the lands.