9mm 147gr col

[Chrisyoung]

I'm new to loading 9mm. I've only loaded around 1500 rounds. I have been loading blue bullets 125 gr tc to a 1.125 col with no problems in my m&p 2.0.  Decided to try some 147 gr fp from precision and I'm have to seat to a 1.070 col to past a punk test In my barrel. Wanting to try them over 2.8 gr of titegroup as a starting load but I'm concerned with the short col. Any help would be greatly appreciated as I plan to keep all my fingers! Thanks in advance. 

[stick]

I've loaded my 147gr bullets at 3.0gr of titegroup @1.130.  For steel challenge loads i use 2.5gr of titegroup with a 1.130 oal.

[Hi-Power Jack]

If The Plunk Test suggests 1.07", then that's what it is (unless you have your chamber reamed).

 

So, I'd back the powder down to 2.6 grains TG and work up, slowly, with a chrono     

 

You should keep all of your fingers, that way....

[4n2t0]

That sounds very short for an M&P, are you sure something else is going on there? Not that 1.07 is a problem but I'd check that measurement because my M&P 2.0 has a very generous chamber.

Edited June 6, 2018 by 4n2t0

[Chrisyoung]

5 minutes ago, 4n2t0 said:

That sounds very short for an M&P, are you sure something else is going on there?

I'm crimping to .377 to .378. using mix range brass I did load some with 2.6 and 2.8 gr of titegroup with no signs of over pressure but I have not chrono yet. I'm beginning to think my gun just doesn't like the profile of the precisions. Any insight in to achieving a long col?

[4n2t0]

Your barrel(s) will determine the OAL. The only thing you can do if you're not comfortable with the short OAL is change bullets. I'd triple check that measurement though. You crimp measurement looks good, so it shouldn't be causing you any problems This isn't an apples for apples comparison but the plated 147gr FP I load at 1.09 for my CZ will easily pass at 1.15 for my M&P. Are you sure the bullets hitting the rifling? Could something else be stopping the spin portion of the test? What about progressively shortening the OAL from 1.15 to 1.07 to see when the round sits flush. Here's a picture to help explain my babbling:

 

 

Hopefully someone who loads the same bullet will come along and confirm that its profile demands a "shorter than normal" OAL.

Edited June 6, 2018 by 4n2t0

[Chrisyoung]

14 minutes ago, 4n2t0 said:

Your barrel(s) will determine the OAL. The only thing you can do if you're not comfortable with the short OAL is change bullets. I'd triple check that measurement though. You crimp measurement looks good, so it shouldn't be causing you any problems This isn't an apples for apples comparison but the plated 147gr FP I load at 1.09 for my CZ will easily pass at 1.15 for my M&P. Are you sure the bullets hitting the rifling? Could something else be stopping the spin portion of the test? What about progressively shortening the OAL from 1.15 to 1.07 to see when the round sits flush. Here's a picture to help explain my babbling:

 

 

Hopefully someone who loads the same bullet will come along and confirm that its profile demands a "shorter than normal" OAL.

Thanks for the info I started a 1.125 at 1.085 it would go but not drop out or spin like they was headspaceing on the bullet going by your picture but didn't get normal headspaceing till 1.07. I bought a small sample pack so I'm not out a lot of I can't get them to work. I've been having good luck with 125gr blues but wanted to get a good 147gr load to to a  Comparison against my 125gr load. 

[4n2t0]

Well it sounds like a bullet profile "issue" but as previously mentioned 1.07 can (and will) be safe. Use up what you've got and move towards a more rounded profile. Being from Canada I cannot make a useful brand recommendation but someone should chime in shortly.

[Hi-Power Jack]

1 hour ago, Chrisyoung said:

 Any insight in to achieving a long col?

 

If 1.07" is the result of The Plunk Test, that's the answer - nothing wrong with 1.07".

 

Just start with light load and work up slowly, with a chrono     

[Chrisyoung]

2 minutes ago, Hi-Power Jack said:

 

If 1.07" is the result of The Plunk Test, that's the answer - nothing wrong with 1.07".

 

Just start with light load and work up slowly, with a chrono     

Thanks for the help. Test some to day and no signs of high pressure. Didn't get any chrono data as I left the battery at home. Going back in a few days with a battery this time to do some chrono and grouping.