Lyman M die slipped .357 boolit

[shooting on a shoestring]

I got a Lyman M die to try, .357 cal. I liked the way the boolits seated after using it, nice and square, but with very little seating pressure. That worried me. Loaded some .38s and some hot .357s.

I fired 49 rounds of .38 3.4 grains Bullseye, 358087 141 grain wadcutter, leaving the lone round in the cylinder exposed to 49 recoils. The boolit slipped forward 0.005". The pistol was a 4" Model 67.

I fired 20 rounds of .357 14.5 grains 2400 Group Buy 175 KSWC, nickel cases, leaving a round in the cylinder subjected to the multiple recoils. At 20 rounds the lone boolit had slipped 0.034 and protruded out of the cylinder of the SP101.

Conclude, Not for use with Nickel .357 cases, OK for .38s.

[mike in co]

its called crimp......

its the crimp that failed.
or an issue with bullet dia and the m die dia...but of the top of my head its crimp failure.

[454PB]

M dies are great when needed, but can cause problems in heavy recoil handguns. You do not want boolits moving forwards in recoil, and many of the slower burning powders get erratic with a light case grip.

I'd rather go with a slightly larger case mouth expander if the boolits are deforming when seated. In .357 magnum cartridges, I generally size .358" and have no deformation problems.

[Buckshot]

.............Heavy loads = heavy recoil = harder alloy = more casemouth grip, and crimp. An important note is that a heavy crimp used with a light boolit pull ain't gonna get you where you want to be. About 34 years ago I made my first revolver purchase. It was a Ruger BH in 357 mag and I had a bag of 50 primed brass I'd picked up from the gunshop. While waiting the 'cooling off' period before I could pick it up I reloaded them with a full book load of W296 and (I think it was) Speer 125gr JHP's.

Lets just say that the casegrip was a bit on the casual side. I was seating and applying a stout roll crimp in the same die. After applying the crimp to a couple cases where the bullet had actually slipped down BELOW the crimp, I decided to pinch the casemouths between my thumb and finger to make sure the bullet stayed put for the crimp. In the process of firing those 50 rounds off it became readily apparent something was radically amiss.

All 50 fired and I didn't have any stuck bullets, but I sure had a bunch of bloopers. I discovered that even though the case was rolled into the cannelure with a vengence you could grip the nose and turn the bullet in the case in a goodly number of the rounds left! I suppose springback allowed that. None of that hit me all at once, but it didn't take too long to realize that casegrip plays a MUCH larger part in the ignition process then the crimp does. Especially with slow powders.

...............Buckshot

[shooting on a shoestring]

Yes, the case neck tension holds the boolit in place more than the crimp.

I was suprised the M die expanded the cases so much as to relieve most of the case neck tension. The M die allowed my .359 boolits to slip fit about 1/4 of the boolit bearing surface into the case. Thats great for aligning and seating the boolits, they go in assuredly straight. The remaining 3/4 or so of the boolit bearing surface had case ID of .357, not enough to hold boolits in place with hot loads, heavy boolits, light revolver.

[mroliver77]

I would polish the spud down some to get better neck tension and adjust die so belling stage only bells enough to get boolit started. I find some older brass does not hold well and relegate that to the plinker box of brass. Top end loads go in new or little used brass.
Jay

[1hole]

The value of high "neck tension" is greatly over rated. Actually, no matter how much smaller the mouth/neck is under bullet diameter is, only about 1 to 1.5 thou matters. The M die provides for that. Try it yourself; measure the diameter of a loaded round, then pull the bullet and measure it again at the same place. The brass simply permanently stretches anything more than the stated numbers so all we get with a tighter starting fit is more seating pressure, Lyman knows that and makes the M die accordingly.

Improve the crimps and you won't pull the bullets. They only need to withstand the recoil of five rounds.

[GP100man]

Try some yeller brass !!!

Mine slip in nickle cases also in the upper loads . I don`t shoot nickle for this reason , but very little !!

What does the expander measure ???

[GabbyM]

You may wish to find someone with a micrometer to measure your bullets and the expander spud. One or the other or both may be off a bit. I've never heard anyone complain of a Lyman M die being out of spec but you know it can happen. Bullet size dies are off diameter quite often. Regardless of brand of manufacture. You can measure case neck ID with calipers. True dimension will be a few tenths larger than indicated due to width of caliper blades. If you've a 9mm J bullet of .355” laying around you could use it as a gauge. Another measurement is to mike the case OD before bullet seating then again after. To see how much you expanded it. Your brass also plays into the equation. Deviation in hardness will alter amount of spring-back after running expander and grip.

There's a lot of details we don't know. Like what you consider to be a tight bullet.

[Wayne Smith]

Why subject it to 49 recoils and 20 recoils? It only has to hold on for four or five. I would say its well within spec and effective if it accomplished it's published purpose.

[atr]

For my .357, I set the M-dies such that the case is opened up just to the point where the gas check is easily inserted into the case mouth. Then I also give it a decent crimp.

[mike in co]

trim them all to lenght, use a conventional bell die and get all the neck tension you want.


having said that......how many holes in your cylinder ??

as the man said they only have to hold for 5/6/7.....yes ??

in a semi auto you test against a full mag for movement on the last one.....

do the same in your revolter...shoot a full cylinder less one...measure the last one.

(someone actually saw the error of the test!)


mike

[7of7]

Why subject it to 49 recoils and 20 recoils? It only has to hold on for four or five. I would say its well within spec and effective if it accomplished it's published purpose.

Exactly what I was thinking... I can remove bullets with a kinetic bullet puller... recoil isn't any different.. Now if they were coming out like that after 5 rounds fired, you should consider a heavier crimp..

[shooting on a shoestring]

OK, I posted a bit hastily, and in fairness to the Lyman M die, some further more rigorous research.

Same batch of nickel plated mixed brass. Yeah that mixed brass pretty much takes this experiment out of being controlled research, but that's what I started with and pretty much all I have that isn't already loaded.

So, theres two pieces selected at random. One just got measured and loaded using the M die. The other was measured and loaded using my RCBS die. Additionally, 24 pieces also loaded with M die, 24 loaded with RCBS.

Plan is to subject the measured round to multiple recoils and measure the boolit slippage.

Here's the M die round's measurements:
M-die spud 0.3555 OD, steps to 0.3600 before the shoulder
Case as fired OD 0.3790, ID 0.3595
Sized OD 0.3733, ID 0.3540
Expanded with M die OD 0.3790 at case mouth over step, 0.3590 ID at step, 0.3550 ID where boolit seats
Boolit measured OD 0.358 to 0.359, is 50/50 WW/pure, AC'd, Felix lube
Seated OD over M die expansion 0.3780. below M die expansion but over boolit base 0.3750

For the RCBS expander plug OD 0.3540
Case as fired 0.3790 OD, ID 0.3600
Sized OD 0.3735, ID 0.3545
Boolit same as above 0.358 to 0.359
Expanded OD 0.3735 ID 0.3545
Seated case OD over boolit 0.3770

Will fire tomorrow and see what happens.

[shooting on a shoestring]

I should add, this load is 14.0 grains of 2400 in .357 cases, will be fired in SP101 (yep sharp recoil).

I know that nickel slips boolits easier than brass, and that I probably won't be subjecting a round to more than 5 recoils in most instances, but, I wanted the boolit to stay put. It did in the .38, which is no surpise. The boolits do seat nice using the M die.

[rockrat]

Hmm, M-die spud is only .0015" bigger than the RCBS expander, but leaves the case .0045-.0055" larger when used?

Maybe you could use your RCBS expander die to expand/flare the case mouth, then just use the M-die to about half the depth you are using it now so as to have greater neck tension. Just a thought

[wallenba]

Would using a taper crimp and then a factory crimp die together be any use dealing with this? I've noticed a minor problem with mine too, but usually only with older thinner brass. Most of my loads are not very hot.

[shooting on a shoestring]

Back from the range with results. Using my SP101, the test round rode 4 shots, was removed and measured for cartridge overall length. So data is in the format: number of shots/COL in inches.

RCBS:
0/1.618
4/1.618
8/1.624
12/1.630
16/1.651 Boolit nose protruded past cylinder face

Lyman M Die
0/1.615
4/1.629
8/1.661 Boolit nose protruded past cylinder face

RCBS wins as expected.

However, this was geared for worst case, nickel cases, heavy boolit, light revolver, hot load. Both were usuable for the first couple of cylinders, but the RCBS did hang on better than the Lyman M Die. Now this is not to say I'm off the Lyman M Die, but for my heavier boolits and hotter loads, I'll continue to use the RCBS. The .38s will get the M Die treatment.

[mike in co]

Back from the range with results. Using my SP101, the test round rode 4 shots, was removed and measured for cartridge overall length. So data is in the format: number of shots/COL in inches.

RCBS:
0/1.618
4/1.618
8/1.624
12/1.630
16/1.651 Boolit nose protruded past cylinder face

Lyman M Die
0/1.615
4/1.629
8/1.661 Boolit nose protruded past cylinder face

RCBS wins as expected.

However, this was geared for worst case, nickel cases, heavy boolit, light revolver, hot load. Both were usuable for the first couple of cylinders, but the RCBS did hang on better than the Lyman M Die. Now this is not to say I'm off the Lyman M Die, but for my heavier boolits and hotter loads, I'll continue to use the RCBS. The .38s will get the M Die treatment.

again the bullet did not move till the eight shot.......you have a nine shot 357 ??

sorry but the "test" makes no sense for revolver ammo

[shooting on a shoestring]

Mike, in a sense I agree with you...but...the Lyman M die cases held the boolit in the cylinder for 20 rounds the first time, only 8 the second. Now I suspect thats due to the mixed brass, but, it happened, and the RCBS held much better.

The point here is that there is a price for the nice way the M die cases seat boolits, and for the advertised extended case life. The price is a little less grip on the boolit. For some applications, not a problem. However, for my SP101 carry piece its a potential problem. If I have to use that weapon, I just may need to fire a few rounds, top off the cylinder, fire a few, top off and it had better not jam b/c some round rode 8 other shots. Plinking, shooting targets, no problem they all get fired before reloading. Shooting outside of the range, can be a very different story.

Understand I'm not bashing the M Die, but when I felt the easy seating in the first rounds I loaded, I suspected it would slip boolits easier than the RCBS and it does. I'll still use it, but not for where I need to get a grip. .38s will get the M die, target .357s probably, defensive .357s no.

[anachronism]

All 50 fired and I didn't have any stuck bullets, but I sure had a bunch of bloopers. I discovered that even though the case was rolled into the cannelure with a vengence you could grip the nose and turn the bullet in the case in a goodly number of the rounds left! I suppose springback allowed that. None of that hit me all at once, but it didn't take too long to realize that casegrip plays a MUCH larger part in the ignition process then the crimp does. Especially with slow powders.

...............Buckshot

I've seen a lot of this in the past, particularly with Remington brass. Now days I segregate my brass by headstamp and only use Remington brass for cast, which typically have larger bullet diameters than jacketed. It did solve that particular issue.

[mike in co]

Mike, in a sense I agree with you...but...the Lyman M die cases held the boolit in the cylinder for 20 rounds the first time, only 8 the second. Now I suspect thats due to the mixed brass, but, it happened, and the RCBS held much better.

The point here is that there is a price for the nice way the M die cases seat boolits, and for the advertised extended case life. The price is a little less grip on the boolit. For some applications, not a problem. However, for my SP101 carry piece its a potential problem. If I have to use that weapon, I just may need to fire a few rounds, top off the cylinder, fire a few, top off and it had better not jam b/c some round rode 8 other shots. Plinking, shooting targets, no problem they all get fired before reloading. Shooting outside of the range, can be a very different story.

Understand I'm not bashing the M Die, but when I felt the easy seating in the first rounds I loaded, I suspected it would slip boolits easier than the RCBS and it does. I'll still use it, but not for where I need to get a grip. .38s will get the M die, target .357s probably, defensive .357s no.

if you get into a fire fight with a short bbl 101 and have to reload somethign is wrong.
and explain how you dump only the empty cases ???

sorry the entire premise is just unreal.

empty the cylinder and reload 6 fresh...if you go beyond one reload something is wrong.....

again the test is not valid for a revolver.

[1hole]

RCBS:
0/1.618
4/1.618
8/1.624
12/1.630
16/1.651 Boolit nose protruded past cylinder face

Lyman M Die
0/1.615
4/1.629
8/1.661 Boolit nose protruded past cylinder face


Okay, were both sets of cartridges crimped exactly the same?

Were both test sets made by using the same type of cases?

[mike in co]

RCBS:
0/1.618
4/1.618
8/1.624
12/1.630
16/1.651 Boolit nose protruded past cylinder face

Lyman M Die
0/1.615
4/1.629
8/1.661 Boolit nose protruded past cylinder face


Okay, were both sets of cartridges crimped exactly the same?

Were both test sets made by using the same type of cases?


probably not.
i see no where in the data that the case were trimmed to length.

no trim=inconsistant crimps

[shooting on a shoestring]

Yes, trimmed to same lenght via Forster trimmer, but I can't say what the lenght is, I'm on the road, but they will be within a couple of thousandths of each other. Same crimp setting on the seating die, same box, just loaded the first 25 using the M die then switched to the RCBS expander for the second 25, kept in order, labeled.

It should be no suprise that the M die slipped before the RCBS. It would have been interesting if the loads with the lesser amount of case neck tension held better. The M die doesn't claim to hold better, just work the brass less than a bell mouth and seat the boolits straighter - due to the over boolit diameter step. The M die works great at what it does, just doesn't have the neck tension I want for my heavy loads.