Crimp on 200 LSWC

I am a long time reloader of both pistol and rifle, and have been reloading 45 for about four years now. On my 45 target loads, I have been using WST at 4.2 gr's and a crimp that usually comes out to around .471 to .470 depending on what brass used, but is usually closer to .471. I have been happy with this as the crimp on the case edge seems to be a good match for 1/16 to 1/8 inch down the case.  The question I am asking is that many, also experienced loaders, on this forum recommend a crimp in the .469 range, and some as low as .468, what is the reasoning for this, as when I have tried to crimp to this, and after pulling bullets to check the crimp, have always experienced what to me would be over crimping of the bullet as to be visibly compressed in at the case junction. I was always taught not to over crimp, but there seems to be two schools of thought as I always had some compressing of the lead at .468-.469. If it matters, I am using Dardas 200 LSWC.

Tighter crimp increases powder burning efficiency.  If you're getting sooty brass and unburned powder increasing crimp can help.

Let your ransom rest be your guide..I do not crimp super tight.
At 8/10 thousand psi chamber pressure for bullseye loads the crimp provides minimal resistance ..

Jerry Keefer wrote:Let your ransom rest be your guide..I do not crimp super tight.
At 8/10 thousand psi chamber pressure for bullseye loads the crimp provides minimal resistance ..

+1!

The first Kart barrel I had on my first wad gun was frustrating at best, until I did some experimenting with crimp levels.  For some reason that tube just wouldn't shoot until I got down to .465.  My load at the time was 4.3 WST, 200 gr Lazercast SWC, Win brass and WLP primers.

Every one of the other 3 Karts like a more normal .468/.469.  The only time I've gotten really good accuracy with .470/.471 was when I played with some Zero swaged bullets.

As Jerry put it, let your Ransom rest tell you what your particular barrel likes.

Al

Crimping to .470 provided the best ransome rest tests I ever ran, unfortunately they did not all cycle a 100% in matches. .469- .468 still gave within a cats hair the same groups but they function 100% every time. Reliability trumps accuracy in a bullseye match

Going below .470/.471 begins to distort the bullet.. The case wall thickness on the average Fed./Win. brass is very close to.010 Starline is closer to .009 On a .452 lead bullet it's getting rather tight.  If your gun is responding to the super tight crimp, I would look at the throat and leade of the  barrel.. Corrected to the proper shape and size, the barrel may shoot better than ever.. As I have said many times, some free bore makes all the difference in the world....

I don't have Jerry, KC or Jon's knowledge level, never will, but the test target I received from Dave SAMs had a pretty loose crimp.  Folks with more knowledge/experience like Jerry could comment on the "why".  I've had great results at .470 and still exceptional accuracy with the tighter crimp and no reliability issues.

Jacketed bullets don't use as much crimp.
Jon

i have the hardest time even measuring crimp...i'm not 100% sure i even do it correctly. When i don't use enough they don't fit in my case gauge.  185 zero jhp

I guess I need to just try crimping some down a bit more, and comparing them to my normal crimp. While I do not have any actual target pistols, two of my 45's are Dan Wessons, a Valor, and a Custom built Silverback, and both seem quite accurate. We'll see if I can tell the difference, with my shooting abilities. May have to look into buying a Ransom Rest someday, as this is becoming quite addicting, and I have shooting berms, and a bench on my property. I also have Wesson 1911's in 9mm and .40 that I load for, so I could probably make good use of it. Any suggestions on who to go to on the purchase of a Ransom rest, and possibly free shipping? Do I just need the rest and a set of 1911 grip inserts? Thanks' everyone, for all your time and help, I do appreciate it.

Christopher Miceli wrote:i have the hardest time even measuring crimp...i'm not 100% sure i even do it correctly. When i don't use enough they don't fit in my case gauge.  185 zero jhp

I hope the article comes though okay, but there was an AMU post on this today.

https://m.facebook.com/USAMU1956/posts/10153065704239734

Setting Adjustment of a Taper Crimp Die

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Seat a bullet to the correct COL. Back out the seating stem. Then with the round in the fully raised ram, screw the die in by hand, crimping as you go. Can not over crimp this way if brass is all the same length. Final test, will round drop in to the barrels chamber? If not, a hair more taper crimp is needed.   The crimp does little to nothing when it comes to burning powder. Neck tension is what matters. The different in case thickness, gives more or less neck tension. A range of 45 to over 100 lbs using different brands of brass. 

Ransome now makes a one-piece unit that combines the rest and windage base into one unit, at a few bucks savings.  Champions Choice and Brownells both carry Ransom products.

Don, Would the windage option be mainly used for ease of centering your groups in a chosen area of the target?

Yes. Without the windage base you are pretty much stuck with using a big sheet of paper and trying to jigger the whole unit around.  This leads to having a unit that is not anchored down well enough.  If you are going to use a Ransom, you need the windage capability and you need to put some real thought into what you will anchor it to and how.  I'm fortunate that my club uses solid concrete rifle benches that must weigh 500 lbs and are anchored into the concrete pad of the firing line.  It does make a difference how solid your mount is.

musky wrote:I am a long time reloader of both pistol and rifle, and have been reloading 45 for about four years now. On my 45 target loads, I have been using WST at 4.2 gr's and a crimp that usually comes out to around .471 to .470 depending on what brass used, but is usually closer to .471. I have been happy with this as the crimp on the case edge seems to be a good match for 1/16 to 1/8 inch down the case.  The question I am asking is that many, also experienced loaders, on this forum recommend a crimp in the .469 range, and some as low as .468, what is the reasoning for this, as when I have tried to crimp to this, and after pulling bullets to check the crimp, have always experienced what to me would be over crimping of the bullet as to be visibly compressed in at the case junction. I was always taught not to over crimp, but there seems to be two schools of thought as I always had some compressing of the lead at .468-.469. If it matters, I am using Dardas 200 LSWC.

Hi Musky, Yes, the lead bullet will always be a microscopically compressed at the crimp site. The deepest compression

will occur near the top of the crimp.. SO WHAT!   with a microscopic compression you've created a bullet with three

driving bands instead the usual two bands(one lube groove bullet).  Think about this, how worried are you about the

 huge compression made at the lube groove site?  

I'm not going to recommend any crimp dimension here but; the developer of the taper crimp die found best accuracy

was when his test loads were taper crimped to .463"(John E. Giles). As has already been mentioned, you will have to

do vised testing to determine what factors give your pistol the best reliability and accuracy.

Tony

I want to thank everyone for their helpful thoughts and suggestions. You have given me some very valid points to consider.  I think my first order of business, is to build a better shooting bench. I guess I am very fortunate to be able to do this on my own property. I have another custom Dan Wesson due any day now, so I guess I need to decide if I should go for it, and order the rest at the same time. I'm sure the best suggestion to me would be to work on my shooting skills more, as both my sons can out shoot me most of the time with my pistols, but it would be nice to know that my reloads are preforming the best that they can be. Also would just be fun, having the ability to adjust loads, and see the affects on accuracy.

Determining crimp for me is just feel...right or wrong.  I resize a case but do not bell the mouth.  I then back off on the seating die and run the case up inside.  Then I lower the seating die until the crimp contacts the mouth and the die stops.  I then back the ram off and very, very slightly screw the seating die down.  When I run the brass back up into the die, I can feel a little bit of contact.  This is not very precise method I know but it satisfies me for my 25 yard loads.  Different brass lengths will have an effect here but I just live with it, besides, 25 yard loads have wiggle room. There comes a point when paying attention to detail has diminishing returns and I prefer to spend more time practicing because that is where the most improvement can be realized. For 50 yard loads, a different level of attention to detail is required.  As far as a Ransom Rest goes, they can be a valuable tool that can either help you or make you crazy.  Successfully using a rest requires proper technique.  Improper technique will yield poor/inconsistent results no matter how good your load is, and you will find yourself becoming obsessed/distracted by undesirable groups.  This will take away from practice time and you will find yourself very frustrated.  I love to practice so the less time I spend on activities that take away from this, the better off I am and the better I shoot.  It seems to me that everyone uses one of just a few suitable powders, the charges all fall within a given range, most guns have either a 10 to 12 lb spring with Kart barrels...so, why should anything much different work out for me in terms of a good reload?  If a gun is built properly, it will shoot one of these typical loads...if not, it won't.  My advice...get a good gun from a well known gunsmith, pick a standard load, do minimal testing to satisfy yourself that it is okay (or leave the testing to your gunsmith) and then spend lots of quality time practicing. As your gun ages and your scores improve, revisit its capabilities on occasion. Don't become rest obsessed. Just my opinion...

The problem with posted crimp # is everyone doesn't do it the same. One mans .472 might be .469 with just a hair more pressure on the jaws, so test your rounds just like the AMU does if possible in your loads with your crimp numbers and try several different ones to find not only the best accuracy but also what functions every time. A round that hits the X @ 50 yards every time but fails too feed now and then is way worse than having 90 rounds that shoot 10 ring@50 yard's every time. Two alibis in the same portion of a match, NMC, timed or rapid means you loose all those points from the second alibi. This can mean the difference between being the national champion and taking home nothing. Function is paramount regardless of crimp.