Leading with 45

[marineshooter]

Hello everyone, I just got a new M&P in 45with a 4 inch barrel. I am using MB softball 230 gr lrn, H-P 38 4.9 grs. seated to 1.250 with a lite taper crimp. oh and Winchester lpp. I am getting heavy leading the first inch of the barrel and quite alot of smoke. More than with the same bullet and 4.5 gr. of Titegroup. It shoots well just wondering if anyone has any ideas.

 

[RealGun]

Hodgdon's suggested load includes a COAL reference of 1.200, which would raise pressure for you and maybe get the bullet to seal the barrel better. The range shown is 4.3 to 5.3gr. Once you try the COAL change, you might want to up the charge a bit.

 

[moxie]

Your 1.250 is not unusual for 230 RNL. I use 1.240 or so with the MBC softballs.

That 1.200 that Hodgdon shows seems awful short. And they use it for both FMJs and RNLs, which typically have different lengths. The site doesn't say, but could those COLs be minimums?

Are you getting all leading and not also some gunk from the lube?

You've got a little more headroom so you might try a tenth or two more.

 

[marineshooter]

I am just getting leading in the first inch or so. I loaded up 100 rds after just 30 -40 rounds you could see the leading just with the slide locked back. I then followed with 10 rds of fmj that did not get it all out. I had to use my Lewis lead remover. I guess that I could seat the bullet .025-.030 deeper and see what happens. I know that if I get close to the max charge of 5.3 they will lead bad all the length of the barrel.

 

[Walkalong]

Try 5.5 Grs HP-38 with an OAL of around 1.260 and see if it leads. If it doesn't, the higher pressure bumped the bullet up to seal things, which would mean that on the first two loads the bullet was too small for the throats and/or bore and/or the bullet was too hard. In that case you would need a softer bullet for the velocity/pressure you were running previously.

 

[rcmodel]

Make absolutely sure your 'light taper-crimp' is indeed light.

Measure a completed round at the case mouth.

If it is smaller then .472"-.473" or so with lead bullets?

You are squishing the base of the bullet down undersize with too much taper-crimp.

Also, make sure you are expanding & belling the case enough it isn't shaving lead off the bullet shank when seating, making the bullet undersize for the bore.

rc

 

[marineshooter]

Walkalong at 5.5 isnt that going over the max charge??? I get that by having the round slightly longer that the pressure would not be over the max. When I had a m&p 45 years ago, I went right up to the max and it leaded the whole barrel. I know that the throat could be slightly bigger or bore but I figured that a s&w would be closer to normal size. I am not a expert or anything but I figured I would ask people who have much more experience than I. I was taught that the only dumb question was the one not asked!!!!

 

[marineshooter]

RC you hit right away. I just measured 8 rounds and I got .468- .467. So I guess that I was squeezing the bullet to small to seal at first. I will back off my crimp a little. Thanks And I am not shaving any lead off when I seat the rounds.

 

[rcmodel]

Imagine that!!


rc

 

[Walkalong]

Walkalong at 5.5 isnt that going over the max charge???

It depends on where you look. 5.0 and 5.5 Grs W231 (Same thing as HP-38) has been used for years. It would suit the purpose, which would be to find out if more pressure cured the leading. But, if you are indeed squeezing the lead bullets too small, it will lead no matter what. You have to squeeze the back half of the bullet to cause leading from gas leaking by.