loading .357sig in a converted .40

Status
Not open for further replies.
B

Bovice

Member
Joined
Sep 27, 2009
Messages
1,601
So I got a factory .357 barrel for my SIG, and it has the 6/8 sights like all their .40s do. I have heard that shooting the regular 125 357 sig rounds in a converted .40 causes the POI to drop a few inches at 25 yards. With that said, I know that heavier bullets for caliber will print higher groups. My question is this-

Can I alleviate the POI shift by loading 147s in .357 sig? I don't plan on changing sights, so I was wondering if any of you had tried to do the same thing.

I can make anything I want, as I have dies. Just trying to see where to go for bullets to try in smaller lots before I commit to 1k. I haven't gotten to the range to try the barrel yet as I have had lots to do at work. But I got a few boxes of S&B to get a baseline for feel, and most importantly additional brass.
 
You need to do your range work FIRST to determine what your actual POI is.
Then you can make an informed decision on what changes are needed.

Considering that a SIG sight only cost $35, switching sites is my preferred method of adjusting POI. I don't like changing loads that I'm accustomed to.
 
converted .40 causes the POI to drop a few inches at 25 yards
Click to expand...


Your sights are not the problem. Your cases are!!!!!!!

When you convert a 40 S&W case to 357 Sig you are skirting on thin ice. A converted case will be shorter (neck) than an actual 357 Sig case. This can cause set back on the bullet when you shoot them. That would be deasterous since the gun could blow up from an overpressure round.

I have a 357 Sig barrel for my FNP-40 and I do not need to change my sights. And yes I reload 357 Sig.

Cases are cheap, guns are not.
Jim
 
I'm using the right cases. Not using necked 40. Just wondering if anyone had tried a heavier bullet and corresponding load to match the POA of the 40 sights. I am not making it a full time 357 so I'm not swapping sights. The 147s make roughly 1200 fps within the load range. I'm trying to get a head start on where to look bullet wise. If it would help POI, I have no problem making a load with a heavier bullet. If it won't help much, I'll just use a quality jacketed 124/125 and live with the shift.
 
As was offered earlier, go with the 8/8 sights and everything will be right. I did the same thing with a P229 in 40 with a drop in 357 SIG barrel. Course I don't shoot 40s anymore. Sight change outs are pretty easy in SIGs
 
Status
Not open for further replies.
Back
Top