Fine tuning loads lee factory crimp die

[Petey308]

There' is logic to what you profess. Neck tension is the key. Brass with uneven neck thickness would not be considered for my needs . I am looking at the collect crimp as a solution to consistent neck tension with out adding bullet run out. I use the Redding competition sizer and seater. . I found that the sizer did more to reduce bullet run out than the seater. Especially when necking 280 down to 6.5. I like to leave a short section of the neck unsized to insure bullet alignment to the bore and just barely kiss the lands. I can only do that with bushing dies. If your chamber is dead true this is I believe is the best way. The only neck size collet dies I am aware of are lee. Any body else produce them. Does t the bullet push any uneven neck thickness to the outside just like a mandrel? Are you measuring run out

The problem with using bushing dies to only size a portion of the neck is that you can run into the same issue I spoke about, as far as not enough uniform neck surface in contact with the bullet. The rule of thumb is no less than the the diameter of the bullet. As in, if you're using .308" bullets, you would want no less than .308" of the neck surface in contact with the bearing surface of the bullet. That is what is key in maintaining minimal bullet runout.

I have used high dollar sizing dies and had good luck with them. I've used the Lee collet neck sizing dies too. I've used the Redding Competition set that has a body die, a micrometer bushing neck sizing die, and a micrometer competition bullet seater. Reluctantly, my testing proved that the cheap Lee full length sizing die with the expander ball removed, in conjunction with a mandrel die, produced the absolute best and most consistent ammo with under .002" runout. My high dollar sizing dies sit and collect dust anymore.

As far as the bullet acting as a mandrel as it seats, yes, it sort of works that way, but if the necks of the cases have become work hardened, they will have spring back. The amount of spring back will vary depending on the thickness of the brass. Thicker areas will have more, and thus produce higher tension at those points on the bullet. This is why annealing and neck turning are part of my process. It undoes the work hardening and ensures uniform thickness. Using a mandrel, and then seating the bullet still seems to be more effective than a bushing die- without neck turning as well.

This has been my experience. I've discussed this with a few others and they've experienced the same things. No one wants to admit that after they spent a lot of money the results are still inferior. Sometimes guys refuse to see the truth as a result. Sometimes, results are indeed different or minimal enough that a conclusion is hard to make.

 

[Petey308]

I agree with the crimp die helping with consistency in neck tension, I also seen data where a primer might start a bullet in motion before the powder is ignited. The crimp die can hold it just long enough to get the powder ignited. Imagine if one cartridge allows the primer to start the motion and the very next cartridge doesn't. The crimp die will make this consistent.

Increasing your overall neck tension, without applying a crimp does the same thing.

 

[Petey308]

I agree with this said, however the avg reloader will not or is not capable of going to these lengths to achieve good repeatable neck tension, therefor for the avg guy a FCD in light crimp is the best way to reduce ES, flyers for med/Long range shooting IMO. Hunters should not jam or touch lands to produce these same results due to field issues with that type loading. Many have said test, I have and for me I get much better ES over a wider range of reloads per case using a FCD with the larger caliber rds. Many reloaders will just call I pulled that flier, when really it was not pulled just one of many neck tension issues that a FCD might of helped with. For a reloader that is only going to reload a case 4 times probably doesn't need one, but if your going to try much more than that I found it helped a lot in Keeping my ES consistent, since I do not go to all the lengths mentioned. Anything more than a Light crimp in my testing hurt accuracy in my large rifles.

Why won't the average reloader be capable of this? It's not rocket surgery doing it the way I mentioned. A Lee FL sizing die and a mandrel setup is cheap.

 

[gohring3006]

Increasing your overall neck tension, without applying a crimp does the same thing.

Yes it does, depends on what equipment I have, on which method I use.

 

[chickm1]

People mostly find a load that works, then try to crimp it, only to find out that the crimped round groups horribly. You have to work up a load, with a crimp, from the beginning. Crimped rounds do not change OAL in the magazine, when the rifle fires. which makes them better if you are hunting, and doing an occasional shot, and loading and unloading. And, just because a rifle shoots a particular round great with powder X, does not mean that powder X will work consistently with powder X. Crimping has it's place, just like anything else, in reloading.

 

[gohring3006]

The problem with using bushing dies to only size a portion of the neck is that you can run into the same issue I spoke about, as far as not enough uniform neck surface in contact with the bullet. The rule of thumb is no less than the the diameter of the bullet. As in, if you're using .308" bullets, you would want no less than .308" of the neck surface in contact with the bearing surface of the bullet. That is what is key in maintaining minimal bullet runout.

I have used high dollar sizing dies and had good luck with them. I've used the Lee collet neck sizing dies too. I've used the Redding Competition set that has a body die, a micrometer bushing neck sizing die, and a micrometer competition bullet seater. Reluctantly, my testing proved that the cheap Lee full length sizing die with the expander ball removed, in conjunction with a mandrel die, produced the absolute best and most consistent ammo with under .002" runout. My high dollar sizing dies sit and collect dust anymore.

As far as the bullet acting as a mandrel as it seats, yes, it sort of works that way, but if the necks of the cases have become work hardened, they will have spring back. The amount of spring back will vary depending on the thickness of the brass. Thicker areas will have more, and thus produce higher tension at those points on the bullet. This is why annealing and neck turning are part of my process. It undoes the work hardening and ensures uniform thickness. Using a mandrel, and then seating the bullet still seems to be more effective than a bushing die- without neck turning as well.

This has been my experience. I've discussed this with a few others and they've experienced the same things. No one wants to admit that after they spent a lot of money the results are still inferior. Sometimes guys refuse to see the truth as a result. Sometimes, results are indeed different or minimal enough that a conclusion is hard to make.

I have tested the caliber to bearing surface interface and I have proven that wrong in regards to runnout. I partial neck size a 30-06 and a 338 lapua with runout less than .002" and single digit SD. I have about .270" with the 06 and .300" in the lapua. The win mag has proven this wrong as well.

 

[chickm1]

Dell, one of the ideas behind crimping, is adding the crimp to make the neck tension more consistent.

 

[Petey308]

I have tested the caliber to bearing surface interface and I have proven that wrong in regards to runnout. I partial neck size a 30-06 and a 338 lapua with runout less than .002" and single digit SD. I have about .270" with the 06 and .300" in the lapua.

Yes, initial runout will be good. That wasn't what I was trying to say. My point was that without sufficient contact, the bullets are susceptible to being bumped out of round. This I have absolutely seen myself. Rounds get discharged from the chamber after a hunt, without being fired, then re-chambered later. Rounds get dropped. Some rifles have terrible geometries in their feed route from magazine to chamber and the bullet gets a lot of resistance when chambering.

All these things can take a bullet out of round and produce negative results. This tends to lead to head scratching because everything was testing/measuring good at the reloading bench.

 

[Petey308]

Personal results will always vary. That's why I stress to do adequate testing yourself to see what results you get. Ultimately you should do what works best for you. I'm just offering my own experience and some science behind it in an effort to backup my claims.

 

[gohring3006]

Yes, initial runout will be good. That wasn't what I was trying to say. My point was that without sufficient contact, the bullets are susceptible to being bumped out of round. This I have absolutely seen myself. Rounds get discharged from the chamber after a hunt, without being fired, then re-chambered later. Rounds get dropped. Some rifles have terrible geometries in their feed route from magazine to chamber and the bullet gets a lot of resistance when chambering.

All these things can take a bullet out of round and produce negative results. This tends to lead to head scratching because everything was testing/measuring good at the reloading bench.

Good point on rounds getting abused. To be completely honest, I don't cycle long range rounds, and I have never put my ammo in a situation where I would be worried about knocking them out of round. But I do know some guys are rough on things. Protecting long range ammo would be one of my up most concerns.

 

[Canadian Bushman]

If you are using a crimp to tune neck tension, why not just tune neck tension?

 

[Petey308]

If you are using a crimp to tune neck tension, why not just tune neck tension?

Precisely. That's essentially all you're doing with a FCD, but also adding potential issues. Keeping things uniform without a crimp is the superior way.

 

[JDD]

Excellent observation improper neck turning , annealing that are expensive and require more skill can cause problems. I bet I got a 1000 bucks in neck turning gear along with the annealer.

 

[Ed Hamlin]

@cohunt great reply. Those who've banged on the op forget what the site is about LR Hunting. I get that competition shooters may not crimp and rely completely on neck tension. to maintain the position of the bullet in the case.

However, competition shoots are not hiking 3-20 miles to have their reticle positioned on the quarry being pursued. It is why ammo for DM's and snipers have a crimp. Banging around in a mag or can can affect the bullet.

I think the better question is what effects have others experienced and documented when crimping or not crimping. Many forget when someone asks a question they are researching opinions or facts, so why shoot them verbally.