Better accuracy needed for coated bullets

[ss+P]

I attempted to load some 147 gr 9mm bayous for production. I used mixed brass with cci primers and a 3 different powders and I can't get the accuracy I am looking for.

I plan on shooting these for the Bianchi Cup as well.

I use a 124gr JHP over 4 grains of Universal at about 130 PF and had a 3 shot group of about 1.5" group at 25 yard. I used a custom 9mm 1911.

I couldn't even get a 6" group with the bayou's.

I loaded all rounds to 1.125 with a crimp of .376. all rounds were shot out of a stock M&P pro 5"

Here is what I tried: all made PF

Universal: 3.0, 3.2, 3.4, 3.6

Titegroup: 2.8, 3.0, 3.4

Clays: 3.2, 3.4

I would like to stick to Universal or titegroup b/c I have a lot of that. is it something with the crimp, OAL, powder or just the quality of the barrel.

I was able to get a 2" group out of the M&P with 124 American Eagle.

[CB45]

Have you tried a 124 gr moly bullet?

Do you have enough bell to prevent bullet shaving as the bullet seats?

[lcs]

Barrel twist rates do not favor 147. Having said that, you need to push 147 faster to get them to stabilize. I have not found a production gun yet that will shoot any 147 with great accuracy at 130 PF.

124 gr are cheaper anyway.

[DougCarden]

Get some coated 122 LFP sized .357-8. Load them to 1.030 with a crimp of .377 and 3.6gr of Titegroup.

If your guns wont shoot that load around 3inches at 50 yds then it is the barrel.....

DougC

[ss+P]

thanks guys. I have been researching a little more and I think the weight of the bullet for the twist rate could be the problem. I did notice that I got some shaving so I will check that.

[Taroman]

If shaving lead is an issue, try a Lyman M expander die.

Does a much better job prepping cases for lead bullets.

[Cherryriver]

Jim Stinar tells us coated bullets (SnS uses the same chemistry as Bayou) need a larger bell than the blue-lube leads because the coating's more sensitive to shaving. Not sure why, but as soon as I widened my bells a lot of things went better when we were changing over to the coated.

[KLR]

Use enough bell to prevent shaving the coating and crimp to .377 or .378. Have not had any issue with set back or with the case gauge.

[tiger49931]

i use 147 gr blue bullets loaded to 1.145 with 3.6 of wst cci primers same hole at 15 yards outta my marauder.

Edited August 12, 2014 by tiger49931

[L3324temp]

I could never get 147's right in my M&P. but the 124 & 135's work well.

[Justsomeguy]

I like 147's in most of my guns, but yes, like FullRace said, you will probably need about 900fps at least to have them shoot nicely in most 9mm guns. Some guns, mostly polygonal rifled ones in my experience, have less luck with 147's, but this is not true of all of them. However, 6" is a pretty large group and something else is going on there if you are not shooting at 100 yards. I would look to the belling and crimping operations as suspect. I have lately been using some SNS coated lead flat point 147's that shoot into about an inch (hey... it's as good as I can hold them!) at 15yrds.

[ss+P]

thanks again. when I get some more 147's I will look at the bell and the crimp and make sure they are both a little larger (so to speak).

[thompsoncustom]

Since there a lead bullet what's the bullet diameter vs the bore diameter?