Terrible accuracy - 357

[deadcenter]

I have a Chiappa 1892 with a 20 inch barrel in .357.

It spends most of it's time indoor at 25 yards. Shoots really well with it's usual load of 5gr GM3 under a 158gr flat nosed lead bullet. Around 900fps.

 

I have shot the rifle at 100 before and it did well with factory PPU 158gr fmj ammo chrono'd at @1650fps.

 

Well........ took it's indoor load to play with at 100 yards and the accuracy was TERRIBLE. I mean all over the place. If the paper would have been big enough - 4 foot group if I was lucky.

The ones that were on paper punched a round hole and were'nt tumbling.

 

Question is (eventually) why would this be. I went with the assumption that a subsonic load would just drop a fair bit but would be nice and consistant.

 

Is it posible that the slow speed caused the immense instability? Should I be realistically be looking at hotter loads for 100+ yards.

 

Anyone's experience and advice welcome.

[Andrew]

I used to shoot 180 grain cast lead bullets from a 6" S&W 38 Special for Hunter's Pistol Silhouette out to 100 yards. I doubt if i was getting 800 fps but could count on reliable hits from a standing position. (The target at 100 is a half sized ram sheep.) What load did you shoot last? PPU jacketed, or the lead? I ask because copper fouling is really deleterious to lead bullet accuracy -especially if using pure lead swaged bullets. If you are getting good groups at 25 yds with the sub sonic loads then your follow through is probably not the issue.~Andrew

[deadcenter]

I was shooting copper plated 158s a bit back but was aware of the copper to lead thing and gave it a good clean with the intent of just shooting lead through it from now on. Plenty of other folks using lead with excellent results.

 

The last 4 to 500 rounds have been lead, the last 200 of so .38s with wadcutters. - clover leaf groups at 25.

These loaded with bullseye. Normally just run a patch or two with brunox through it before putting it away, same ritual for the past few years.

 

In the past for hotter lead loads I've used 2400 and for the top end stuff H110 with jacketed bullets.

 

The nickel plated brass I was using is on it's last legs - maybe an issue, but was rather surprised by the bad results this time out.

 

The bullet design is very blunt nosed. I sometimes use truncated cone types but the they don't always feed as well as the others.

 

Next time I take it out, I'll try something a bit faster. Might also try a few of the same load with new brass just to see if there is any difference.

 

Maybe I found the exact opposite of the sweet spot

[gbal]

Hmmm.....I see your puzzlement.

From what you say,it does not seem likely that the copper-lead issue is valid-would that in any case cause such extreme bullet dispersion:

You seem to have the same lead 900fps indoor load shooting clover leafing at 25 (so calibre moa) yet this same load shooting 50moa at 100y ('four feet',but clean round holes-no tumbling,suggesting no extreme instability). IT's pretty hard to get a modern firearm to shoot 50moa,so something is radically out of kilter.

The two (.357 to 50 moa) rather suggest some 'in flight' issues,rather than just velocity loss-which should be as you predicted-low but just a larger 'group',not a spray effect!

Doubtful that even a very loose scope on a rifle would do that,though you may not have one/or checked it.

 

 

Change the 'last legs nickel' cases.

Reload with more MV in better brass,maybe 'better' lead bullets? (as saddler)

Try again at 100y.

 

Which is what you suggest-sensibly-so let's see if things improve.

 

gbal

[deadcenter]

I'll shoot whats left of these 'bad' loads at 25, see what they do.

 

As you suggest, load for higher velocity with some different bullets. Might even do a few with the same ones just to see.

 

The bullets are the GM ones from Kranks. The 158 RNFP.

 

Something I didn't look at was the sights. The standard fixed ones. Never an issue before, but as we all know, doesn't mean that's the case now. I'll have a look now actually.

 

Thanks for the replies gents.

[MrCetrizine]

For what it's worth, I use 158gr LOS plated bullets from blackrifle.co.uk with 15gn of H110 and get stunning accuracy from 25 to 100m.

[deadcenter]

Thats what my H110 load was with the Los bullets. Also gave good results but after about ten shots the mirage from the barrel was quite bad. Seemed a bit overkill for 25 but it certainly is fun. I chrono'd these at about 1650fps, range officer used to frown at me a bit. Not really a problem but I stood out when everyone else was well subsonic.

 

Maybe my usual load for the indoor stuff and the hotter one for everywhere else.

 

I was just surprised as I've never had this rifle perform badly before.

[deadcenter]

Shot some of the rounds that performed badly at 25 yards tonight and they shot like they always do - quite well.???

 

Also shot some 158 truncated cone, the 158 RNFP that I had the prob at 100 with and some 148 semi wad cutters over 12gr of 2400. All at 25 yards.

 

All performed well. The SWC perhaps the best. Going to try this load next time I'm out at 100 next weekend.

 

See what happens.

[Miseryguts]

Shot some of the rounds that performed badly at 25 yards tonight and they shot like they always do - quite well.???

 

Also shot some 158 truncated cone, the 158 RNFP that I had the prob at 100 with and some 148 semi wad cutters over 12gr of 2400. All at 25 yards.

 

All performed well. The SWC perhaps the best. Going to try this load next time I'm out at 100 next weekend.

 

See what happens.

Hi deadcenter, I would be interested in the results of your tests, as I am trying to push my Win 94AE 357 out to 100 yards. My subsonic load seems good(ish) at 25 and 50 but 100 is poor, so need to look at a hotter load? Am using VvN320 under plated LOS 158gr TC bullet. Any pointers gratefully received!

When I get the 357 sorted, will be onto my Henry 44mag next!

[deadcenter]

I'll update my findings as and when I get chance to shoot.

 

Lots of people shoot 357 out further than 100 so I'm sure it's just a matter of working up a load just like any other.

I think I just wrongly assumed that pistol calibers would just be a matter of load up according to load data and as long as the load was consistent, it should be ok. Clearly not.

 

Oh well, I'll work on it as time permits.

[farmer7]

I'll update my findings as and when I get chance to shoot.

 

Lots of people shoot 357 out further than 100 so I'm sure it's just a matter of working up a load just like any other.

I think I just wrongly assumed that pistol calibers would just be a matter of load up according to load data and as long as the load was consistent, it should be ok. Clearly not.

 

Oh well, I'll work on it as time permits.

I was in the same boat recently trying to find a subsonic load using cast bullets that would shoot consistently at 100 yards and closer, I'm there now but took a bit of fiddling.

 

Using jacketed high velocity loads accuracy was was never a problem, as were 158gr GM RNFP loads at 1250 fps but slow them down to 1000-1050fps groups opened up to 10-12 inches at 50 yards, perhaps 2" at 25 yards.

 

It was suggested I needed a softer alloy than the 20bhn or so GM bullet so I tried 6 different cast bullets from other suppliers which didn't improve things much so I got fed up and thought I'd try some GM 180gr TC. They have been brilliant from the start but i've settled on 4.0gr of Bullseye, they are averaging right on 1000fps from an 18.5" Marlin and very happy with accuracy using a peep sight. Groups below shot from the elbows over the bonnet of the land rover, I've no doubt they'd be better with a scope!

 

So I'd say you can have an accurate subsonic load to 100 yards. Maybe your rifle might get on better with a heavier bullet too? For whatever reason mine just wouldn't group them well at 50 yards but like yours no evidence of instability. The 180gr has transformed It!

 

Targets:

25 yards http://i.imgur.com/OKmhmWj.jpg

50 yards http://i.imgur.com/nH16ls6.jpg

100 yards http://i.imgur.com/ncrZVV7.jpg

[deadcenter]

Wow, that's exactly what I'm looking for.

 

The PPU 357 factory jacketed stuff was ok for me also, but not great. These chrono'd at around 1650fps - 20" barrel. Barrel heated up quickly and the heat haze was terrible. Good fun but............

 

Most of my shooting is at 25 yards and high velocity was not a priority, so I was intending to keep a 99% lead diet for the rifle. Stoke some jacketed up occasionally just for fun.

 

I'll get some 180's and load some up. I also use Bullseye so this might work.

 

Thanks for the info, much appreciated.