375 RUM- Gibbs (Box Monkey Express)

[Taylorbok]

I got the idea from 375 ultra mag thread.
I decided to do a 375 Rum with a 40* shoulder, moved ahead .053" and taper reduced to .006"
A guy over on that forum had done a similar cartridge several years ago and called it the 375 Box Monkey Express.

Initially I tried to seat the bullet hard into the lands to jam the case head against the bolt face but that wasn't working. I believe the firing pin strike was pushing the case onto the bullet causing excessive head space and I was almost getting case head separations. I ended up having to neck them up to .416 and then size back down to .375 and make a false shoulder (wish I'd have taken pictures of those cases). I ended up with some fairly crooked necks so I had to trim off a bit more than I would have liked.

I have the intention to run this rifle at Ko2M Canada which has a 10k Joules limit, I was hoping to get the 390gr A-tips to 2900 fps. which I can get it there but the node seems to be around 2870 unless the barrel speeds up which I'm not expecting now. I have about 140 rounds through it (including 100 FF)

-Formed case on the left, Factory brass right.

I did initial powder test 104-110 gr and never saw pressure to stop (I don't have this data handy)

Second powder ladder was 107-112gr N570, with 390 A-tips. BTO 3.177" (barrel 32" long, 1:9 twist)
107- 2830 fps
108- 2840 fps
109- 2875 fps
110- 2893 fps (very faint ejector mark)
111- 2898 fps (light ejector mark)
112- 2940 fps (light ejector mark, Bolt click at top)

Next I went to testing load stability. I did 5 Shot groups and on paper they all shot the same about 1.25" which I am not happy about so I hope I can bring that in with seating depth.

108 - 2858 fps, ES 9, SD 3
109 - 2881 fps, ES 8, SD 2
110- 2887 fps, ES 39, SD 16
111- 2906 fps, ES 43, SD 20

At 111 I started to notice a very slight click at the top of the bolt throw, that and the massive ES makes me want to stay away from here. I wish I would have loaded 107gr to see if the window goes that low. I am planning to run powder charge at 108.5 gr and do a seating depth test. I also have a couple new tricks to hopefully lower ES/SD a bit that I didn't do to these cases.

I also need to add some weight to the rig. It weighs about 20lbs. I have a steel arca rail coming that is about 3lbs and then I will likely add a bipod extension and a belly weight and see where it ends up.

I will try and post some groups when I get to seating depth testing.
I also have some solids to try at some point but I wanted to shoot these a-tips for the splash.

In the end I don't know if the effort of custom reamer and dies was worth it for the few FPS over what the standard chambering is doing but it's fun to learn. There is a few guys can say "I told you so" but I've got my fingers crossed it still picks up 30-40 fps

 

[wildcats]

Barrel twist?

 

[Taylorbok]

Barrel twist?

1:9 twist. I'll add that to the main post. Thanks

 

[wildcats]

" I ended up with some fairly crooked necks so I had to trim off a bit more than I would have liked."
Did you use nk sizing mandrels to neck up ,or just a .375 sizing button .
Years ago i did a 338-375 lapua and a 408-510 wildcat,necked up the cases using mandrels in different increments without any problems of nk and shoulder distortion.

 

[Taylorbok]

" I ended up with some fairly crooked necks so I had to trim off a bit more than I would have liked."
Did you use nk sizing mandrels to neck up ,or just a .375 sizing button .
Years ago i did a 338-375 lapua and a 408-510 wildcat,necked up the cases using mandrels in different increments without any problems of nk and shoulder distortion.

I used a mandrel. I started with 375 RUM brass from ADG, the only reason I had to go up ( .416) was to create a false shoulder. I'm not sure why they were so wonky, they sized fairly easily. My second 50 turned out much better, instead of trimming them down to be flat off the bat I fire formed them first and that seemed to straighten them out, I didn't have to take as much off those ones but only problem now is I essentially have 2 different sets of 50 brass, I can always shorten the second batch so they are all the same.

It was just the neck that was weird it like had a wave in it, should have taken pictures of that also.

 

[camotoe]

I bet that puppy would cook 300gr 338....

 

[Taylorbok]

I bet that puppy would cook 300gr 338....

Stay out of my head. Lol.
I have a 338 barrel sitting here along with 338 Edge dies and brass but I’ve been considering doing this same thing to a 338 case.

 

[Taylorbok]

Well I can’t get it to stop spraying A-Tips. I’ve tried seating depths from touch all the way to .120 off. And I tried backing charge weight all the way down to 104gr. I always end up with 2 touching and one about 1” away. It was shooting SMK’s well during FF.
I also put some 375 CEB MTH in it just to try with a random powder charge and 5 went into 1/2” group.

Im gonna try some N565
Any other suggestions I really wanted to shoot the A-Tips.
Here’s a pic of my last target. These were all the same charge with seating depth test but my charge weight test looked nearly identical

 

[SIDS01]

I got the idea from 375 ultra mag thread.
I decided to do a 375 Rum with a 40* shoulder, moved ahead .053" and taper reduced to .006"
A guy over on that forum had done a similar cartridge several years ago and called it the 375 Box Monkey Express.

In the end I don't know if the effort of custom reamer and dies was worth it for the few FPS over what the standard chambering is doing but it's fun to learn. There is a few guys can say "I told you so" but I've got my fingers crossed it still picks up 30-40 fps

Information is worth exactly what you pay for it, nothing more, nothing less. You own what you learned.

I did 3 wildcats based on the 338 Lapua case 5-6 years ago. A shortened 7mm version with a 35 degree shoulder, and 40 degree Improved 7mm and 30 caliber versions. Loose, likely denial based, accounting put the cost of a reamer, headspace gages, and dies at ~$600 each.

They gave lessons on how to model overbore cartridges in QL, the impacts to barrel life, and a better understanding of how velocity affects score. I had a KO2M day 1 sort of course set up for testing. Targets went from 1200 to 2300 yards and were 1.5 - 2 moa on their largest dimension. When you have a course like that, it's not hard to find people to shoot with. I shot a few times a year with other ELR shooters I'd met at local competitions and picked up their ideas as well. I turned a lot of bullets inside out and managed to get a 7mm jacketed bullet through a free hanging 1/4" plate.

The most sobering lesson I've had came from shooting local 2000 yard matches with a factory RPR in 300 prc using ammo that fit in the magazine and used Hornady brass. Under conditions that the RPR would go 50% hits on a 2 moa target, a 36" 375CT would only get half again as many hits. My 33XC could match it, but not out score it during the last 50 rounds of it's barrel life.

My take on it is velocity doesn't matter until it does and that's a lot farther out than most think. Long before that, starting at a mile or so, the problem is dominated by velocity and BC spreads. That assumes a gun that'll shoot 1/2" to 3/4" 5 shot groups every time. For the guns typically used at 2000 yards, a fps is about the same as moving the target 1 yard closer. If you want to figure out how much BC helps, use your solver and compare time of flight. The rubs are 100 fps takes about 10,000 psi more and if you increase the velocity or BC spread, you're effectively making the target smaller much faster than you're moving it closer.

I did a quick check on the Monkey Box and came up with a net gain of 2.2 grains of water capacity increase. I did it quickly and it's been awhile, so the math may be off. The accounting gave the reduction in body taper gave 1.4 grains, moving the shoulder forward gained 3 grains, and the steeper shoulder had 2.2 grains less capacity. The capacities are close enough that the same powder will likely be used and it'll take around another grain to match the peak pressure. If the peak pressure is the same, the only increase in velocity will be from an increase in the average pressure down the barrel from the additional powder. The velocity increase will be small.

The problems I've had with low case body taper are in the sizing die and in chambering. Too much lubrication is removed during the early part of sizing and the lube needs to be reapplied to the top of the case once or twice to avoid sticking cases. The chambering issues might be the product of my process on a manual lathe. I prebore the chamber at the case taper with a boring bar to give the reamer a concentric start. I set it up to give about an inch of reamer travel. At 0.012"/" of taper, the reamer cleans the chamber out and leaves a great finish. At 0.009"/" I need to be very careful with the sizing and finish the boring leaves. If your guy just shoves the reamer in, find another guy. Looking at your brass, I think your guy is doing something similar to what I am.

My take on wildcats is I won't be doing anymore 40 degree shoulders, will probably be leaving the case taper at 0.012"/", the neck length will be at least 1 caliber and the freebore set to put the rear of the bearing surface about 1/3 the way down the neck as the bullet contacts the lands. I may relax on the case taper because contemporary cartridges use 0.009 "/" and I've been forced to learn to chamber them, but a 30 degree shoulder will be preferred to 35 degrees.

 

[SIDS01]

Initially I tried to seat the bullet hard into the lands to jam the case head against the bolt face but that wasn't working. I believe the firing pin strike was pushing the case onto the bullet causing excessive head space and I was almost getting case head separations. I ended up having to neck them up to .416 and then size back down to .375 and make a false shoulder (wish I'd have taken pictures of those cases). I ended up with some fairly crooked necks so I had to trim off a bit more than I would have liked.

I have the intention to run this rifle at Ko2M Canada which has a 10k Joules limit,

The firing pin doesn't move the case forward. The ejector is already holding it there. The best bet on wildcats is to short chamber them for the brass you actually have. You've probably already internalized that lesson.....

How does that 10kJ limit work? Are cartridges banned outright by their headstamp or is the actual ammo tested for bullet weight and velocity?

 

[SIDS01]

Next I went to testing load stability. I did 5 Shot groups and on paper they all shot the same about 1.25" which I am not happy about so I hope I can bring that in with seating depth.

108 - 2858 fps, ES 9, SD 3
109 - 2881 fps, ES 8, SD 2
110- 2887 fps, ES 39, SD 16
111- 2906 fps, ES 43, SD 20

If those velocity spreads hold for 10 shots, I'd go with 108 grains and call it good. There isn't a lot left on the table with an ES of 20 for 10 shots and there isn't anything near or below 10 fps.

When I have a pressure ladder like that and I think the velocity is still low, I start with testing if the case fill is too high. Move to a lower charge of the next faster powder.

I've never found anything in the case prep that would extend it.

 

[SIDS01]

View attachment 8200771

Tracking is your friend. If you can add stand offs to get the bag rider parallel to the bore and the bipod mount square to it, the gun will recoil closer to straight down the bore. Moving the top of the recoil pad to just over the top of the bolt will align the support with the recoil impulse.

Adding weight around the bore is the best for tracking. Heavier barrel contours are a cheap way to do that. The courses I shoot have enough change in elevation between the targets that I prefer to keep the bipod controls within reach. Adding weight to the back of the gun has an effect similar to extending the bipod forward but doesn't require compromising your position on the gun. It's a personal preference and I recognize I'm swimming against the current. I use buffer tubes and bag riders made from steel round stock to add weight in back. If it's not a chassis gun that uses an AR style buffer tube, I'll make a recoil pad spacer from 1-1.5" thick rectangular steel bar.

 

[Taylorbok]

@SIDS01 I actually need to check how much capacity I gained. I will try and do that today or tomorrow and report back. I'm having fun doing the wildcat thing, so far everything is working out aside from I can't get it to shoot the A-tips well. I've got a couple different loads/ seating depth to try and some N565 before I abandon them for the time being and just shoot CEB MTH that I have for the Ko2M Canada.

One regret I have is not going to bushing dies so I could control neck tension better but I didn't wanna have to remove the threaded insert from my press every time. Looking back that was half the reason I bought a 50 Cal sized press.

I'm really happy with the velocity spreads on that load but 1" or bigger groups just wont cut it.
That target posted above with seating depth test had ES of 11 and SD of 3 across all 15 shots, just the group size is wack

The firing pin doesn't move the case forward. The ejector is already holding it there. The best bet on wildcats is to short chamber them for the brass you actually have. You've probably already internalized that lesson.....

How does that 10kJ limit work? Are cartridges banned outright by their headstamp or is the actual ammo tested for bullet weight and velocity?

I had the ejector out for fire forming to try and allow the bullet hard jammed into the lands to hold the brass to the bolt face but I believe during firing the brass was able to slide onto the bullet creating excessive headspace and near case head separation. The false shoulder solved that problem it was just another step not a big deal but I did lose about .0005" neck thickness in the process.

Cheytac cartridges are banned by name. After that it would be pretty much impossible for anyone to know if you had a cartridge that produced over the limit. That being said at Ko2M they told us if they suspect a competitor of being over the limit they would chronograph and you'd be disqualified from the competition if you were over the limit.

I do need to address some tracking issues but I'm going to just battle it for this year, I don't have time to make a bunch of changes before competition. This rifle will go back to a 30 Sherman Mag after this and I plan on building a new rifle dedicated to ELR at that time I'll go to a stock that is more conducive to ELR. I did actually take the ski feet off and stopped using my protektor bag, I think with all the angles like you mentioned was causing a bit of extra vertical in my groups. It wasn't a huge improvement but a hard shoulder and loading into the bipod helped me manage the recoil better vs just sliding on the feet.

 

[Taylorbok]

If anyone is curious I just measured H2O capacity and on average I picked up 6.5gr of H2O capacity.
I filled both cases to the neck shoulder junction with N570 and my version holds about 9gr more but if you wanted to seat the bullet in the standard case farther out and fill powder into the neck you'd be able to close the gap for sure.

 

[Sandow the Heretic]

Have you asked Bertram about Ultramag cases with no formed shoulder? They are making edge brass so getting a straight wall case to you of the right length is actually less work for them and you can just size it down and trim.

Other option might be to just cream of wheat form them. Never tried necking up with that but it aught to work just fine. Just for the love of god, take your muzzle brake off!

-Alex

 

[Taylorbok]

Have you asked Bertram about Ultramag cases with no formed shoulder? They are making edge brass so getting a straight wall case to you of the right length is actually less work for them and you can just size it down and trim.

Other option might be to just cream of wheat form them. Never tried necking up with that but it aught to work just fine. Just for the love of god, take your muzzle brake off!

-Alex

I’ve got formed brass now and it seems to be working, next go around I may try and get some straight wall cases to size myself.

About the brake. Are you saying that because it’s huge and ugly or just to see how it shoots? Because that was like the second thing I tried and it didn’t help at all. I guess I never mentioned that.

 

[cameljockey230]

The wavey neck for those wondering is at the case mouth not the rest of the neck and using imperial sizing die wax on your entire case while fire forming will help.
The 40 degree shoulder and less body taper while giving a slight increase in volume keeps the brass from moving around and moves the turbulence point backwards further helping the throat live longer.
Creating the false shoulder keeps the firing pin from driving the case forward and to test that out to see if it's true or false load a round with the bullet touching the lands without powder and a inert but unfired primer.
Put the round in the chamber pull the trigger and measure your overall length. If it's shorter the firing pin strike moved the case body.
The key to the false shoulder is getting the length so you need to palm the bolt closed and then not running your brass into the chamber until your going to fireform it.
To test that prep 20 cases then run 10 into the gun and close the bolt and leave the other 10 unmolested.
Dimensionally the 10 not originally chambered will always come out better and you won't get any failed to fire rounds because the case moved forward on you.
If you go to The Cream Of Wheat method start at 15 grains of fast powder but you still need the false shoulder to prevent the case from moving in the chamber.
If your guns bedding is good try a faster powder and if that doesn't work and a different primer doesn't help just use a different bullet.

 

[Sandow the Heretic]

The wavey neck for those wondering is at the case mouth not the rest of the neck and using imperial sizing die wax on your entire case while fire forming will help.

It will also massively increase bolt thrust. This is a poor mans proof cartridge essentially. Wouldn't do it.

-Alex

 

[Taylorbok]

If your guns bedding is good try a faster powder and if that doesn't work and a different primer doesn't help just use a different bullet.

I had a bit of success last night. I seem to have found 2 loads for the A-tips that are shooting about 1/2-3/8” one with N565 one with N570. The CEB MTH are shooting well also with N570. I’m going to take these loads out to 1000 and see how they hold up. I’ll also be able to analyze the splash from the solids. I forgot to turn my Labradar on for the N565 so I don’t know what it’s velocity spreads look like. (Rookie mistake).

A-tips with N570 I had to back the load off a grain and give them a massive jump. (.120) the load is slow but it shoots better anyways.

If I do another barrel in this chambering it’ll be on a larger action with a much heavier contour. The heavy Palma with a .375” hole is definitely not lending any help. All about learning.

 

[cameljockey230]

It will also massively increase bolt thrust. This is a poor mans proof cartridge essentially. Wouldn't do it.

Yes one needs common sense when dealing with gunpowder and firearms in general.

The bolt thrust is how it all works in producing great brass.

For those with no common sense don't run with scissors always wear a helmet when riding a bike never ride in the bed of a pickup truck and eating bacon is bad for your health and work up your loads slowly

 

[Sandow the Heretic]

The bolt thrust is how it all works in producing great brass.

I can't say that makes the most sense. with good normal case sealing in the chamber the neck and shoulder will blow out to fill the available space. With the case lubed up I would think you would draw material from the point of mechanical resistance which is the end of the web. Thinning out just past the web does not have a happy ending most of the time...

-Alex

 

[cameljockey230]

I can't say that makes the most sense. with good normal case sealing in the chamber the neck and shoulder will blow out to fill the available space. With the case lubed up I would think you would draw material from the point of mechanical resistance which is the end of the web. Thinning out just past the web does not have a happy ending most of the time...

-Alex

It should make sense because that method produces the best possible brass.

It also is a fireforming step so your proof load comment makes no sense. You work up a load that is lubed the same as any load. You wouldn't work up a full house load with fireformed brass then go backwards and use that as your lubed fireform load.
The false shoulder on a round that has never been chambered holds the case stationary while the imperial sizing die wax allows the rest of the brass to perfectly or more perfectly fit the chamber. If you test the fit of each piece of false shouldered brass in the chamber it is no longer snug enough to produce the best possible brass. You simply sacrifice the first piece while adjusting the die.

Without the false shoulder is when you would see the thinning around the web because the only thing holding the brass from moving forward is the extractor. His original case now has 0.053 of forward shoulder movement so nothing including a jammed bullet will hold it against the bolts face like a properly setup false shoulder.

Edit to show how the US military used to grease there ammo for 03 competitions.

 

[Taylorbok]

I’m sure the lubed cases would work. But not sure I’m down with that. I was blaming the wavy mouth on the brass not being perfectly centred on the mandrel. I think next go around I’ll get an expander die blank and have my smith ream it with my chamber reamer and then open the neck up so the case goes in straighter see if that helps.

 

[cameljockey230]

The wavy mouth issue has 2 sources.
One is the brass thickness isn't uniform.
The other is how the brass clings to the neck of the chamber.

 

[Sandow the Heretic]

It also is a fireforming step so your proof load comment makes no sense.

A proof load tests the action strength by putting higher than normal mechanical loads on it. Brass in normal operation expands to fill and grip the chamber and reduces bolt thrust as a result. A lubed case reduces this reduction in bolt thrust by preventing the case wall from gripping the chamber walls. Removing the brass and even opening the bolt may not be noticeably different but the effect of fire forming a bunch of lubed cases is a sustain increase in stress on the bolt. Most actions are way overbuilt so you aren't likely to blow one up but it is still bad practice.

-Alex

 

[cameljockey230]

A proof load tests the action strength by putting higher than normal mechanical loads on it. Brass in normal operation expands to fill and grip the chamber and reduces bolt thrust as a result. A lubed case reduces this reduction in bolt thrust by preventing the case wall from gripping the chamber walls. Removing the brass and even opening the bolt may not be noticeably different but the effect of fire forming a bunch of lubed cases is a sustain increase in stress on the bolt. Most actions are way overbuilt so you aren't likely to blow one up but it is still bad practice.

-Alex

I am well aware of what a proof load is and actually have proof ammo for the 50 bmg cartridge.
Lubing the outside of a fireform load is common practice in 600-1000 yard benchrest competition to produce the best possible brass.
I believe your history is with the 50BMG with limitations placed on your chambering except in unlimited class so the practice is less common there. They in essence foolproof the lightgun class to keep the cartridge alive but strangled the wildcatters into unlimited class.
The difficulty here is your assuming everyone will develop a match load then lube the case and get increased bolt thrust.
The case in question has 0.006 taper per inch or half of a typical Ackley Improved case coupled with 0.053 longer shoulder which is resulting in wavy neck syndrome.
The brass is sticking to the chamber walls to soon and not evenly forming another common wildcat issue with that kind of taper per inch.
If he is fireforming and I believe his original post to be true as written he would lube the cases 1-5 then develop his load using cream of wheat and pistol powder or start low and work his way up just like any normal reloader does stopping at any sign of pressure and debunking the proof load assumption.
By the way proof loads test the action and chamber not just bolt thrust.
I don't own his book but I am sure someone viewing will have a copy and tell us if P.O.Ackley cut the locking lugs off of a action Then fired it to demonstrate the bolt thrust on his designs? Is that true?
Good reloading practices should always be followed but I am sure if this was a reloading forum shooters would tell us about the time they didn't remove the case lube and shot full house loads instead of fireform loads or shot in the rain with wet brass and frosted the outside of the body of the case.

 

[Taylorbok]

@cameljockey230 my wavy necks came when making the false shoulder not while fire forming. Fire forming actually helped to straighten them out. I could see lubing the case and firing with COW would help even farther

 

[cameljockey230]

Since all you did to create the false shoulder was run a mandrel into the neck then size most of the neck back down the brass itself was most likely the culprit.
Which is why the benchrest crowd turns necks to get a uniform release on the bullet.

Out of curiosity how is extraction with 0.006 taper per inch if you don't mind me asking?

 

[Taylorbok]

Since all you did to create the false shoulder was run a mandrel into the neck then size most of the neck back down the brass itself was most likely the culprit.
Which is why the benchrest crowd turns necks to get a uniform release on the bullet.

Out of curiosity how is extraction with 0.006 taper per inch if you don't mind me asking?

could be. The extraction is flawless. The bigger concern I have is it extracts so well pressure is very hard to detect. I got into decent pressure testing some N565 but my chrono died and I have no idea what the velocity was on that round.

 

[Taylorbok]

I am very impressed with how the bipod extension helps recoil management.

Here is a group from the A-tips at 1260 Yards. My arca rail fell off and I never got to shoot the MTH bullets for group at distance, I'll have to upsize the screws to keep them from breaking off. I tried shooting them using my range bag as a front rest but that didn't seem like a fair comparison. I wasn't super disappointed about the off target splash from the solids but when they hit they barely take any paint off

 

[Sandow the Heretic]

I am very impressed with how the bipod extension helps recoil management.
View attachment 8225175

Here is a group from the A-tips at 1260 Yards. My arca rail fell off and I never got to shoot the MTH bullets for group at distance, I'll have to upsize the screws to keep them from breaking off. I tried shooting them using my range bag as a front rest but that didn't seem like a fair comparison. I wasn't super disappointed about the off target splash from the solids but when they hit they barely take any paint off

Accutac sells an extension for the locking lever. Might be worth considering. That and different feet. The stock ones have a habit of grabbing and bouncing. Fine on little guns but anything we shoot is going to move and it is better to let it move smoothly rather than try and restrain it.

The splash difference on miss is condition dependent. When you are getting good dust clouds it hardly matters. When it has rained or if you are shooting into red clay, the jacketed bullets kick more up. At 375, you are at the transition point where solids are usually going to be faster at the muzzle and the longer supersonic range is probably worth it over the visibility of misses. By the time you get up to 50 cal, the solids can be upwards of 300 fps faster. It is interesting looking at the breakdown now but at Ko1M almost everyone there uses jacketed bullets and at Ko2M it is just the reverse.

-Alex

 

[Taylorbok]

Accutac sells an extension for the locking lever. Might be worth considering. That and different feet. The stock ones have a habit of grabbing and bouncing. Fine on little guns but anything we shoot is going to move and it is better to let it move smoothly rather than try and restrain it.

I have the ski feet. I tried them for a bit but couldn’t get used to them so I figured go back to the normal feet for the match and I’ll give them a better chance next year. I’ll look into that lever extension tho, thanks.

 

[Earnhardt]

What is your load combo with the groups at 1260 yards?

 

[Taylorbok]

What is your load combo with the groups at 1260 yards?

I actually ended back at 108gr N570 with about .005” into the lands. 2860 fps.

I’ve started to think the heavy recoil from this round in this fairly light package was exploiting every little flaw I had and I just needed some time behind it to learn to shoot it better. That or the barrel just started to shoot better because it’s doing really well now.

 

[Earnhardt]

And what is the freebore again?
Thanks

 

[Taylorbok]

And what is the freebore again?
Thanks

Here is the reamer print if you want it. .2900" Freebore.

 

[Earnhardt]

Thanks!

I already have a 375RUM reamer, with .300 freebore. Thanks.

 

[Taylorbok]

Just thought I'd report back Ko2M Canada didn't go as hoped. I was second last shooter hottest part of the day, full sun, rank mirage on a flat range. Spotter could barely pickup splash, I couldn't see anything.

Had hits out to 2000 meters but barely scored any points.
Spectators said the gun was shooting great groups at distance and they could see the corrections we were making in the splash. Splash was much easier to pick up from there, it's a bit elevated.

In the end I'm happy with how the rifle performed just needed to be able to see, going to plan to build a new rifle based around this cartridge for next season for some more weight and better tracking.