OAL 40 cal questions

[ger]

Thanks in advance for the help.

I just bought a used Brazos custom limited and have been reading about the loading longer for the STI guns. Previously I was loading for a CZ 75 SA.

So is the longer loading purely for a more reliable feed? and if the gun seems to feed fine at 1.13. should I just leave it there?

Is accuracy improved as well?

Last I also seem to remember some talk of barrels being a little different for some custom guns and was wondering if this was true for the Brazos. ( I am not sure if I was understanding it correct as I have been spending hours reading these forums and get side tracked)

I just loaded up and shot some 180 MG JHP, OAL 1.195 with vv 320 from 4.9 to 5.1 grns, crimp at .418. It would seem I saw others getting to major PF. I was not able to get there. Its not a problem as I will just go back to the bench and start bumping it up, but I figure I could also reduce OAL some but then the consistent research shows most going 1.20.

maybe I have just read to much or not enough

[G-ManBart]

You could always ask Bob at Brazos what he recommends for an OAL....I'm sure he's got a preferred length. 1.195-1.20" is a common number and yes, it's almost entirely for feeding reliability. The longer OAL help limit the possibility of a nose dive (it hits the ramp before it gets a chance to get nose low). I would suspect that accuracy isn't hurt and may very well be enhanced with the longer OAL as it makes for a shorter jump to the rifling, which is almost always a good thing.

If the gun is running at one particular OAL, the smart thing to do is leave it there and then make the powder charge whatever it needs to be to make Major.

Don't worry too much about not making PF with the same charge as everyone else. Some barrels are faster than others and some are slower. I know other folks have had to go over 5.1gr to make Major.

[JakeMartens]

I talked to Bob about this at Area 6 on a used Brazo's I bought.

He recommends to go to 1.22-1.25

He has info on this on his website, at least he did but I couldn't find it tonight

He has a load recommendation as well with a Montana Gold 180, N320, winchester small rifle primer and a oal at 1.22

I would give him a call, he can set you up

[ger]

hmmmm, calling the guy who makes the gun.

thats makes to much sense and way to easy for me to have thought of on my own

I would suspect that accuracy isn't hurt and may very well be enhanced with the longer OAL as it makes for a shorter jump to the rifling, which is almost always a good thing.

He recommends to go to 1.22-1.25

This is actually great info to me, as I shot some Blazer Brass at local match in a pinch and a RO was asking what kind of bullets I was shooting as they appeared to look like they were tumbling by the the look of the holes in the target. When I got to my reloads no such observation was made was made.

Thanks for the knowlege and I shall give him a call Monday.

[bkeeler]

oal at 1.22

He does recommend a 1.220 OAL with 180gr Bullet.

FWIW:

I have an STI tuned by Brazos and I load WSP or WSRP ,1.220 OAL, 180gr MGB JHP and 4.8 gr TG or 5gr N320.

Start out 10% lower and work up to get your PF and check for pressure signs.

Works great. This was the load he recommended for me when I bought the gun from him.

BK

[ger]

so I tried a 5.1 grn vv 320 with a 880 fps avg. OAL 1.195, is it possible for velocity to go up with less powder and greater OAL?

Thanks

Ger

[ger]

just thought I would post up my final findings in case anyone else has similar questions or is researching as I was on the forums here.

Ended up with a180 grn MG JHP, OAL 1.22 , 5.3 vv320 , power factor of 171. Should anyone find this useful also understand as was stated to me many times here, start lower and work your way up.

Thanks again to all who pointed me in the right direction.