Why is first round so slow? (.38 Spl in Lever Action)

[mongoose33]

I've been reloading .38 special to use in my Rossi R92 38/.357 Lever Action, in preparation for some Wild Bunch 3-gun stuff, and when I've been chronoing them a strange pattern emerges--the first round is far slower than all the rest.

In a variety of loads, this is what I get:


Hi 812 894 927 985 993 985
Lo 763 650 766 814 810 798
Av 795 838 886 907 904 906




It doesn't matter the loads, though the first four are me working up through progressively higher Bullseye loads, and the last two a couple of 4756 loads, but in EVERY case, the LOW round is the first round.

And it's really low compared to all the rest.

Question: why?

I'm crimping these into plated bullets, and I've pulled some and there's a clear crimping groove, so I don't believe the bullets are being set back after the first one--and the amount of recoil isn't that serious anyway.

I've run a couple of loads through using linotype cast bullets and I don't get the same effect.


I've searched on the web for this issue, and can't find anything on it. Any insight?

 

[WestKentucky]

Could be a couple things. Either your "cold bore" shot is through a cool barrel that has contracted as metal does as it cools and it squeezes the bullet tighter basically applying a set of brakes to the bullet, or if you clean the bore between shots you may be creating some fouling in the bore that serves to seal the bullets after that first round dirtys up those couple ten thousandths of an inch. In this case the first is leaking pressure from behind and probably leaving bullet material deposited in the bore.

 

[tightgroup tiger]

The barrel is getting hotter and expanding reducing friction a little? Just a guess.

 

[WestKentucky]

Just reread and saw that the issue disappears with Linotype bullets. They are generally of slightly larger diameter and are designed to seal better. It's almost certainly the second scenario from my post above. I suggest you slug your bore and measure it carefully. Compare bullet measurements to your bore. I'm betting you have measurable leakage past your bullet which is in the form of hot gas that melts off a portion of the lead or copper jacket and deposits part of it inside the barrel.

 

[Crunchy Frog]

You do know that Wild Bunch rules require the use of lead bullets (no plated)? The rifle is supposed to be at least .40 caliber but some clubs allow the .38 rifle in monthly matches. Our club does, but when we host the State Match on August 30-31 the big bore rifle rule will be in effect.

 

[mongoose33]

Just reread and saw that the issue disappears with Linotype bullets. They are generally of slightly larger diameter and are designed to seal better. It's almost certainly the second scenario from my post above. I suggest you slug your bore and measure it carefully. Compare bullet measurements to your bore. I'm betting you have measurable leakage past your bullet which is in the form of hot gas that melts off a portion of the lead or copper jacket and deposits part of it inside the barrel.

I'm going to have to pursue these ideas above--I've examined the bore, can't see any sign of deposits, though it's harder through those lever actions to see that.

The linotypes were sized, and they're also lighter. I should have noted and forgive me for not, but the plated bullets are Rainier 158gr HP, and the linotypes were cast in a lee mold that produced very large diameters so I had to size them down. They weigh about 123 gr.

All of them shot wonderfully accurately.

I didn't let the bore cool down all that much between groups.

You do know that Wild Bunch rules require the use of lead bullets (no plated)? The rifle is supposed to be at least .40 caliber but some clubs allow the .38 rifle in monthly matches. Our club does, but when we host the State Match on August 30-31 the big bore rifle rule will be in effect.

It's a local group running a variation of wild bunch. We'd be laughed out of an official version--in fact, we don't even holster the 1911, we pull it off a table.

I dithered on whether to get the Rossi .45 LC or the .38/.357, and since locally we allow the latter, I figured it would be cheaper to shoot.

I have no doubt that at some point I'll have a second Rossi in .45 LC, and a buddy here has offered to let me use his .45LC if I ever do something sanctioned.

But I appreciate the heads-up.

 

[rcmodel]

What powder & charge are you using?

One thing that comes to mind right off hand is powder position in the case.

You load them, then carefully chamber the first one, sight the rifle over the sky-screens, and fire the first round.
With the powder all back in the case against the primer flash hole.

Then, the gun recoils.
And the other rounds in the mag get the crap knocked out of them and the powder is spread thinly from front to back in the case.

Next shot, the primer fires and has a much larger flame surface area of thinly spread out powder that all ignites instently.

Which hits the bullet in the butt much harder, expanding it in the bore tighter, and raising pressure & velocity higher.

Try another string, but raise the rifle vertcle after loading each round to settle the powder in the case the same each shot, and see what you get?

Thats all I got tonight!

rc

 

[Walkalong]

One thing that comes to mind right off hand is powder position in the case.

My guess as well, especially with 4756 which is very position sensitive until the pressure gets up there. 1st shot powder forward, then the rest powder back or level would do that.

Hanging the rifle bore down before the first shot, then remaining fairly level for the rest?

 

[mongoose33]

Thanks for the theories, esp. about powder position. I saw this effect with 4756, Bullseye, and 231 all, so it would not appear to be powder-specific. I didn't notice this when I shot the commercial ammo at the beginning but I was more focused on accuracy at first so I don't know. I will of course norm all this with commercial ammo to begin with, see if I can reproduce this with the commercial ammo.

I did try tilting the gun muzzle-up before firing, didn't seem to make any difference, but I didn't do it systematically.

I'm going to reload some more and take them out and try out some of these theories and see what I can nail down. I will, of course, report back. Not sure I can do it today. We've been invited to my brother-in-law's mother's house for "dinner" which is over noon--and may completely screw up the entire day. The food will be good, but shooting would be better.

RC: This happened with Bullseye loads up to 4.1gr, and 4756 up to 5.6gr. It also happened w/ a 231 load of 4.7gr but I didn't report it above as the pattern was already darned clear. .

My goal was to approximate the velocity of commercial ammo in the same bullet weights and styles. AmEagle 158-gr. LRN ammo produced 976fps in a string of 9, Win 130-gr FMJ produced 937fps in a string of 19.

*******************

Not that this matters at one level, but I have been sucked into the world of casting. I've reloaded and shot cast for years (Missouri Bullets), but you know, this is my hobby, I like learning, I like experimenting, etc. etc. etc. So a friend who casts his own bullets, drips his own shot, cleans lead up from many sources before turning it into ingots, agreed to show me. I had a single LEE mold already bought, and after that, lights-out. I'm absolutely entranced by this. I want to learn about it all.

So I do have the Rainier plated bullets, but I'm looking for a good cast load for the Rossi. And then I'll work on bullets for the 9mm (same mold may suffice quite well). And I have some Lyman #2 from my friend, and some Linotype from him, and....this is like the tar baby. Once you start, you can't pull away.

Or in the immortal words of the Eagles: You can check in, but you can't check out!

But man--this first round low stuff is really weird. I've worked up...well, a lot of bullet/powder combinations over the years, for handgun, .223, .270--and I've never seen this. It may be the rifle, may be the caliber, may be the powder, may be...well, whatever it is, I'm going to learn something. And I like that.

 

[Walkalong]

I saw this effect with 4756, Bullseye, and 231 all, so it would not appear to be powder-specific.

They are all position sensitive to one degree or another. Some are very good, and some are poor. SR 4756 is very poor in that regard at low levels. I tested a load with 4756 and a 125 gr bullet in .357 cases that gave 900ish FPS powder back, but stuck the bullet both times I tried it powder forward.

 

[ArchAngelCD]

I know you are supposed to shoot only lead bullets at Cowboy Action matches. Do they allow plated bullets in the Wild bunch matches?

I agree, it sounds like a powder position problem. Either that or your first cold bore shot is effected by the clean cold bore. (or a combination of both)

 

[buck460XVR]

I agree, it sounds like a powder position problem. Either that or your first cold bore shot is effected by the clean cold bore. (or a combination of both)

I suspect the cold bore. Either the clean bore is creating more friction or the warm bore creates less friction on the plating. I shoot levers and even the act of racking the first cartridge from the tube mag into the chamber turns the gun so the powder is not going to be any farther away from the primer than any other subsequent shots. Most times the barrel is up when I rack in the first shell. Unlike the loading of a revolver where the gun is generally loaded with the barrel pointed downward and the gun raised to level when shot.

 

[mongoose33]

I know you are supposed to shoot only lead bullets at Cowboy Action matches. Do they allow plated bullets in the Wild bunch matches?

I agree, it sounds like a powder position problem. Either that or your first cold bore shot is effected by the clean cold bore. (or a combination of both)

We're just starting to do this kind of thing around here, so we're not strict adherents to the rules. We will tighten that up over time, but right now, we're more interested in gaining people interested in doing it.

We don't draw handguns from holsters, for instance. Some of us do a more traditional Cowboy Action approach, down to the period guns, outfits, hats, the whole nine yards.

Not me. I'd rather use more modern guns, but that's just me. An 870, a Rossi .38 special lever action, and a 1911.

We do a version--and I don't know how close this is to the official rules--where we start w/ a loaded but not chambered shotgun on a table, safety on. When we start, we rack four rounds, shoot four popper targets (hopefully!), leave the action open, and lay the shotgun back down on the table. We use carpet samples on the tables.

Second stage--about 15 yards to the left--is a lever action, 10 rounds loaded, action closed. We aim at four silhouette targets about, oh, 15 yards away. One shot on the first, two on the second, three on the third, four on the fourth.

After that, third stage is a table closer to some other silhouette targets. An unloaded 1911 sits on the table, two mags loaded with 5 rounds each. Again, one round on target one, two on target two, two on target three, reload, another round on target three, then four rounds on target four.


I don't know how close that is to the actual real CA rules, but I find it fun, and it's close enough for me now. When we get more people going, I'm sure we'll tighten up the rules so if people want to go other competitions, they're ready.


I was actually shocked at how much I enjoyed it. Sucked me right in!

 

[mongoose33]

I suspect the cold bore. Either the clean bore is creating more friction or the warm bore creates less friction on the plating. I shoot levers and even the act of racking the first cartridge from the tube mag into the chamber turns the gun so the powder is not going to be any farther away from the primer than any other subsequent shots. Most times the barrel is up when I rack in the first shell. Unlike the loading of a revolver where the gun is generally loaded with the barrel pointed downward and the gun raised to level when shot.

I took a half a day today to go and see if any of these theories seem to account for this.

Short answer: likely the cold (or in some cases, relatively cooler) bore.

I observed this first round slow using Win FMJ commercial rounds, as well as a number of handloads using the plated Rainier bullets.

Even when I let the rifle cool down some, where the barrel was still warm, I often observed this disparity--first round slower.

Each time I ran 5 or 10 rounds I also ran a boresnake through just to remove any residual contamination as an influence.

But it was fairly clear that this was at least the 'proximate cause of the variance. It had nothing to do with accuracy (well, not at the 10- to 15-yard range which is all the further I shoot when testing rounds for velocity. I figure if I can put successive 3 or 4 rounds through the same hole in the paper it's accurate enough.

BTW, this was observed much less with lead or linotype bullets. It was only the FMJ commercial or the plated Rainier bullets with which I tended to observe this.


I appreciate all the help and ideating here. I have some more experimenting to do, because I want to work up some good cast bullet loads for competition.

 

[ArchAngelCD]

I can understand not forcing correct dress right a way and even not having to be an official member of SASS right a way but if it were my match I would insist on obeying the rules as to guns and ammo. It sounds like you are have a great time, obeying the match rules as to guns and ammo will not take away from the fun in the least.

IMO it's not a good idea to have shooters practice one way and then force them to change everything they are doing at a later time.

The link I'm providing will give you the rules for the Wild Bunch Match, the directors rules and more importantly the RO Rules. (Range Operations rules)
http://sassnet.com/wildbunch/wbRules.php

Have a great time, you picked a fun match to play in...

 

[rcmodel]

Short answer: likely the cold (or in some cases, relatively cooler) bore.

I still just have a hard time thinking that is the reason.

But to find out for sure?

Heat up the barrel real hot before firing the first shot with a hair dryer, heat gun, or propane torch first.

rc

 

[mongoose33]

I can understand not forcing correct dress right a way and even not having to be an official member of SASS right a way but if it were my match I would insist on obeying the rules as to guns and ammo. It sounds like you are have a great time, obeying the match rules as to guns and ammo will not take away from the fun in the least.

IMO it's not a good idea to have shooters practice one way and then force them to change everything they are doing at a later time.

The link I'm providing will give you the rules for the Wild Bunch Match, the directors rules and more importantly the RO Rules. (Range Operations rules)
http://sassnet.com/wildbunch/wbRules.php

Have a great time, you picked a fun match to play in...

I understand what you're saying. My motivation originally was simply to force some stress into the shooting process so that should, heaven forbid, I ever am forced to use a weapon in self-defense, I'll at least have a chance.

Then I found out it was fun.

I don't figure it matters much w/r/t the lever action caliber. I've shot both the .38/.357 as well as the .45 LC, and I hit what I aim at, as a general rule. A bud has a .45 LC Rossi he said I can borrow should I ever desire to compete for real. Which I probably will.

We're pretty aggressive with range safety, nobody's walking around w/ loaded weapons.

Actually, I do have to disagree with you on one thing--learning new variations of the rules is something that creates more stress, and greater challenge, and I like that.

Thanks for the link!

 

[mongoose33]

I still just have a hard time thinking that is the reason.

But to find out for sure?

Heat up the barrel real hot before firing the first shot with a hair dryer, heat gun, or propane torch first.

rc

I can probably simulate that by running about 30 rounds through it in rapid succession!

 

[Crunchy Frog]

I know you are supposed to shoot only lead bullets at Cowboy Action matches. Do they allow plated bullets in the Wild bunch matches?

I agree, it sounds like a powder position problem. Either that or your first cold bore shot is effected by the clean cold bore. (or a combination of both)

This from the WBAS Handbook:

"Pistol and rifle ammunition may not be jacketed, semi-jacketed, plated, gas
checked, or copper washed. It must be all lead. Molydisulfide coated bullets,
polymer coated bullets, or equivalent are acceptable."

Wild Bunch, like SASS cowboy action shooting, uses steel targets at relatively close range. The rules mandate lead bullets in a specific velocity range (maximum 1000 fps for pistol, 1400 fps for rifle) for safety reasons. With properly mounted targets, the lead bullets fragment and dig a little trench in the dirt in front of the targets. A jacketed or plated bullet may bounce back and ruin your fun.

Some clubs that are building interest in WBAS relax some of the rules. In my club's regular matches we allow the use of a .38 caliber rifle. A friend of mine helps run matches at his home club in the Florida panhandle; in their fledgling WBAS matches they will allow a 1911 in any centerfire caliber and of any barrel length. I have heard of clubs allowing pump shotguns other than a Winchester '97 or Model 12.

I would not compromise safety rules. I agree with flexibility in other areas with the caveat that if you deviate too far afield you lose what makes the game distinctive.

 

[wrangler5]

You can check the powder-position issue pretty easily if you have access to some Trail Boss. You can basically fill your 38 Special cases with Trail Boss - to the base of the bullet but not enough to compress the load. You'll get fairly low velocities, and will not get anywhere near the pressure limit for the round. (My 158g lead bullets are only going in the high 600s out of a 3 or 4 inch revolver barrel - but they're very accurate and I can shoot 'em until I run out, with no pain.)

You won't get any powder shifting in the case with those loads, so if you still get a significantly lower velocity on the first round of your string you'll know it's due to something else.

 

[Walkalong]

He is using plated bullets, and Trail Boss doesn't play well with plated. It is easy to check with what he is using now. All he has to do is try it.

 

[mongoose33]

A bit more data on this.

Made up a bunch of my own cast bullets (starting to learn that) and loaded up 10 in my Rossi.

I jacked in a round, then tipped the rifle muzzle up, and tapped the forestock a few times to settle the powder down against the primer, leveled it out at the target and fired across the chronograph.

Wowie! 150+ fps faster than the other rounds jacked in with the rifle held vertically and powder settled down.

I was using IMR SR 4756, which worked ok, but holy cow--I had one round, and this is .38 special I'm loading, hit 1250fps, which is starting to approach .357 mag velocity.

I'm going to have to find a powder that fills the case virtually completely, maybe Trail Boss is what I should try. Other suggestions gratefully accepted.

 

[rcmodel]

Hmmmmm?

Right back to post # 7 again now are we?

rc

 

[mongoose33]

Hmmmmm?

Right back to post # 7 again now are we?

rc

Why yes, yes we are. I finally was able to get out and do some of those things. These weren't plated rounds, just Lyman #2 alloy.

None of this matters a whit w/r/t the 3-gun stuff I'll be doing, as the distance to target isn't enough to matter.

I'd sure like to have more consistency though.