Range Report, First batch tested, need some advice.

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Range Report, First batch tested, need some advice.

Postby mcb » Tue May 23, 2017 8:43 am

So I tested my first batch of reloads (first shots ever in my new 450 Bushmaster AR) this past weekend. All in all the gun ran well. The only functional issue I had were a few failures to feed from one magazine. Otherwise all my loads cycled the gun with no jams or failures to eject.

Image
Glad I brought the sissy pad for the butt stock. I have waffle tread bruise on my should from A2 butt stock and the first fifteen rounds. Then I wimped out and put the pad on. My shoulder thanked me. The recoil was not horrible and for hunting with hunting clothing on I think it would have been fine but shooting over a bench with only a T-shirt on and that A2 butt stock the recoil got to me eventually.

Weather was about 75F and humid, with overcast sky. My chrono is an old Chrony Alpha Master set about 12 feet in front of the muzzle. My target was set just 45 yards down range. Once I have a load or two I am happy with I will setup for some longer ranges. I plan on zeroing it at 100 or 150 yards for hunting.

I had three bullets each with three incrementally higher powder charges. I weight every charge on my scale after it dropped and trickled to met the load.

First was 230gr FMJ (Armscor)
Pushed by Lil'gun and lit by WSR primers OAL 2.065
These are 5 shot averages except as noted
33gr Avg: 2120fps ES: 165.7 SD: 64.98
35gr Avg: 2186fps ES: 150.5 SD: 86.04 (3-shots)
37gr Avg: 2294fps ES: 102.8 SD: 41.96

Image

That was about what I expected velocity wise maybe even a touch faster than expected from my QuickLoad workup but the extreme spread and standard deviation was pretty bad. The 33gr group is missing as it was used to bring the new scope reasonably close to point of aim.

Second was 240gr XTP/MAG Hornady OAL 2.060
Pushed by Lil'gun and lit by WSR primers
These are 5 shot averages except as noted
32gr Avg: 2132fps ES: 30.99 SD: 12.36
34gr Avg: 2203fps ES: 30.12 SD: 13.11
36gr Avg: 2297fps ES: 147.7 SD: 63.77 (4-shots)

Image

So the first two charges were what I would expect for extreme spread and standard deviation what happen on the last one? You can even see the group size open up on that one. The flier in the 34gr group was totally on me I flinched on the last shot of the group.

And finally was 300gr XTP/MAG Hornady
Pushed by H110 and lit by WSR primers OAL 2.065
These are 5 shot averages except as noted
30gr Avg: 1653fps ES: 87.73 SD: 34.59
32gr Avg: 1739fps ES: 106.2 SD: 44.08
34gr fat-fingered the chrono and lost the data but this charge shot one of the best groups.

Image

Surprisingly this load was a bit more comfortable to shoot even with the last load that I expect should have been right at or just above 1800fps with that big heavy 300gr bullet. More push than the sharpness of the lighter bullets.

That was a lot of rambling and pictures. My big question, assuming you got this far, is what can I do to tighten up my velocity spread? I would like to see that extreme spread well under 50 fps if I can. First thing that comes to my mind is I did not crimp enough. I used a relatively light crimp on these first loads since 450BM headspaces of the mouth. I may have overdone(underdone?) that. My crimp was roughly .476 but I was afraid to crimp too heavily especially with the cannelure on the XTP. What other things could be causing such large velocity spread? Thanks!
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Re: Range Report, First batch tested, need some advice.

Postby Hoot » Tue May 23, 2017 2:24 pm

Some of those 100yd groups are good for the two bullets you chose. Neither are known for being tack driver material.

That first group smacks of "death grip" on the rifle. At least that's how mine look when I clench it too tightly. Those 300 grainers crave speed to get them to shoot tight. They come into their own around 2k fps and beyond. I also use QuickLoad and while I have not used it with H110, I know from experience that it way over-predicts W296 in this caliber.

If you are using new brass:
About all you can do to tighten them up is seat the bullets until you almost bury the cannelure and taper crimp down to .474. You want to drive that mouth down into the cannelure. Don't worry, they will headspace down .460. That's not to say you should taper crimp below .474. That seems to be the sweet spot for cannelured bullets in this caliber. There are esoteric measures you can take like deburring the flash holes and normalizing the primer pockets. I do that on all my brass, but the 800 pound gorilla is the crimp. Above all and IMHO, do not expand the mouths before seating the bullets. You never get as much mouth tension squeezing brass down after seating as you do stretching it out to accept the bullet while seating. That Hornady seating die pretty much keeps the bullets aligned so that you don't need the mouths belled out.

If you are reloading fired brass:
You can decrease the SD by either wet pin tumbling your cases or degreasing the inside of the mouths as deep as you expect the bullet to seat using q-tips and a strong HFC or CFC solvent. You don't need to douche them, just moisten the q-tip and holding it against the inside of the case, roll the case around to make sure it wipes out the "umma-gumma" that vibratory tumbling leaves behind. After a few cases, if that q-tip isn't dirty, then chances are you won't need to do the rest. When I used a vibratory tumbler, the q-tip would get dark gray to black after about 2 cases and I'd reverse it and do 2 more. That residue impedes the lock that you get from clean brass on clean copper.

Its all about Neck Tension.

BTW, there is a SIMS Limbsaver, slip-on recoil pad thats black and not so telltale that you're using a "sissy pad", which I prefer to call a "shoulder saver". If you get the slip on Limbsaver, get the medium size. It fits an A2 stock perfectly. FWIW, all my AR lowers wear either an A2 or A1 stock. Not fond of stocks that like like a prosthetic lower leg. ;)

Lest I forget, Welcome Aboard!

Hoot
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Re: Range Report, First batch tested, need some advice.

Postby mcb » Tue May 23, 2017 3:23 pm

Thanks Hoot, next batch I will back off the bell to zero ( I only used a little on the first batch) and I will tighten my crimp to .474 and we'll see how much more consistent my velocity gets. I also really like the idea of degreasing the case mouths. I have already decap and resized my brass so I can clean the case mouth and remove the sizing die for the tool head.

My brass is once fired a friend gave me. It's all from Hornady factory ammo.

I agree that Quickloads always seem optimistic on H110/W296 in almost every cartridge I have ever tried it in. 357 Mag is just as bad as 450 Bushmaster was. That said it under predicted the Lil'gun loads by about 80-100fps. Win some, loose some.
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Re: Range Report, First batch tested, need some advice.

Postby Jim in Houston » Wed May 24, 2017 4:59 pm

I'm wondering if you should shoot some factory loads as a base line, just to see if you get the same variability as you do with your hand loads? I would suggest 10 or so rounds, just to average out any quality variations in individual rounds. Here are some results I got for 63 rounds that I shot at different times.
Rounds 63
High 2,294
Low 2,060
Average 2,169
Median 2,164
Spread 234
Sigma 57

A high standard deviation seem built in, but I can still get good groups on any given day.
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Re: Range Report, First batch tested, need some advice.

Postby mcb » Mon May 29, 2017 9:03 am

I got to stretch it out a bit yesterday. I loaded up a new batch of the 240gr XTP/MAG. Cleaned case mouths, weight every charge, and tapper crimped to 0.474 inch. I did not get to chrono this batch but I did get to stretch out the range. Started with sighting in at 150 yards. Group size was not good ~6-inch group at 150 yards. It would put 3-4 rounds in a 3-inch group and then throw a round or two out to 6-7 inches. Stepped out to a 10-inch steel plate at 200 yards and hit it 4 out of 5 shots with proper hold I had calculated ahead of time for that velocity, bullet and zero. So I am not totally disappointed at the typical range (<120yards) I will be hunting at I will have no problem hitting a deer where I want too but I would really like to see something at or less than 1.5 MOA accuracy at 200 yards from this gun to be really happy.

I am going to run over to the local Cabelas and see if I can get some 250gr FXT bullet to try.
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Re: Range Report, First batch tested, need some advice.

Postby Hoot » Mon May 29, 2017 3:56 pm

mcb wrote:I got to stretch it out a bit yesterday. I loaded up a new batch of the 240gr XTP/MAG. Cleaned case mouths, weight every charge, and tapper crimped to 0.474 inch. I did not get to chrono this batch but I did get to stretch out the range. Started with sighting in at 150 yards. Group size was not good ~6-inch group at 150 yards. It would put 3-4 rounds in a 3-inch group and then throw a round or two out to 6-7 inches. Stepped out to a 10-inch steel plate at 200 yards and hit it 4 out of 5 shots with proper hold I had calculated ahead of time for that velocity, bullet and zero. So I am not totally disappointed at the typical range (<120yards) I will be hunting at I will have no problem hitting a deer where I want too but I would really like to see something at or less than 1.5 MOA accuracy at 200 yards from this gun to be really happy.

I am going to run over to the local Cabelas and see if I can get some 250gr FXT bullet to try.


I suspect Jim might have meant to try a box of actual factory ammo, not just the same bullets, to establish a baseline.

Hoot
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Re: Range Report, First batch tested, need some advice.

Postby mcb » Mon May 29, 2017 8:47 pm

Hoot wrote:
mcb wrote:I got to stretch it out a bit yesterday. I loaded up a new batch of the 240gr XTP/MAG. Cleaned case mouths, weight every charge, and tapper crimped to 0.474 inch. I did not get to chrono this batch but I did get to stretch out the range. Started with sighting in at 150 yards. Group size was not good ~6-inch group at 150 yards. It would put 3-4 rounds in a 3-inch group and then throw a round or two out to 6-7 inches. Stepped out to a 10-inch steel plate at 200 yards and hit it 4 out of 5 shots with proper hold I had calculated ahead of time for that velocity, bullet and zero. So I am not totally disappointed at the typical range (<120yards) I will be hunting at I will have no problem hitting a deer where I want too but I would really like to see something at or less than 1.5 MOA accuracy at 200 yards from this gun to be really happy.

I am going to run over to the local Cabelas and see if I can get some 250gr FXT bullet to try.


I suspect Jim might have meant to try a box of actual factory ammo, not just the same bullets, to establish a baseline.

Hoot


I just need to find some loaded ammo local or order some, but i think I will manage to get some reloads working by deer season. I could live with what I have so far but I got time to make it better. I did get the last box of 250gr FTX and a box of the 225gr FTX and another pound of Lil'gun at Cabelas today.
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Re: Range Report, First batch tested, need some advice.

Postby Hoot » Tue May 30, 2017 5:07 am

mcb wrote:
I just need to find some loaded ammo local or order some, but i think I will manage to get some reloads working by deer season. I could live with what I have so far but I got time to make it better. I did get the last box of 250gr FTX and a box of the 225gr FTX and another pound of Lil'gun at Cabelas today.


You'll love those 225's. Load them with 38gr of Lil Gun seated to ~2.12 COL. You should be able to just see a little bit of the cannelure peeking over the mouth. Use as little taper crimp as it takes to get the job done. Try 5 at .476, 5 at .475 and 5 at .474, as an experiment. Measure that diameter as close as possible to the mouth. It is after all, a taper. I have made it a habit of raising the ram until I feel the crimp resistance begin and then short stroking it up over the course of 3 or 4 pulls until I hit the stop. Kind of a tap-tap-tap.That encourages the case to shimmy a little into the absolute center of the shell holder by the final tap. If you have your press lubed, you will feel it get slightly easier to run the ram to the final stop as the case is centered.

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Re: Range Report, First batch tested, need some advice.

Postby mcb » Tue May 30, 2017 6:21 am

Hoot wrote:
mcb wrote:
I just need to find some loaded ammo local or order some, but i think I will manage to get some reloads working by deer season. I could live with what I have so far but I got time to make it better. I did get the last box of 250gr FTX and a box of the 225gr FTX and another pound of Lil'gun at Cabelas today.


You'll love those 225's. Load them with 38gr of Lil Gun seated to ~2.12 COL. You should be able to just see a little bit of the cannelure peeking over the mouth. Use as little taper crimp as it takes to get the job done. Try 5 at .476, 5 at .475 and 5 at .474, as an experiment. Measure that diameter as close as possible to the mouth. It is after all, a taper. I have made it a habit of raising the ram until I feel the crimp resistance begin and then short stroking it up over the course of 3 or 4 pulls until I hit the stop. Kind of a tap-tap-tap.That encourages the case to shimmy a little into the absolute center of the shell holder by the final tap. If you have your press lubed, you will feel it get slightly easier to run the ram to the final stop as the case is centered.

Hoot


Yeah I found your earlier thread on the 225gr FTX and my first load was going to be basically what you just listed above. Thanks for the work and advise. Hopefully I get some loaded this week and tested this weekend.
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