Neck sizing resulted in full resizing after the 5th magnum case reload

[Deleted member 10043]

Being doing some reload testing with a .300 H&H, which is my first magnum grade bolt action rifle. Everything is fine in the accuracy department. Today I shot a lot of brass that has been necked sized four previous times. The previous time out with the same lot I had one case that would not extract when the bolt was pulled backed. Neck sized and reloaded the lot again. Today, nearly two-thirds of the neck sized cases did not extract when the bolt was pulled back. Subsequently, I did a full resize on the same lot and they all extract now. Am I at the end of brass life or is this typical for large magnum cases?

 

[demolitionman]

I'm not familiar with Mag style casings, but when it comes to neck sizing cases, eventually they get to the point you will have to FL size them again, and after firing you can go back to neck'n them only until they are difficult to eject. Pretty normal what your dealing with. I get about the same amount of reloads off of neck sized cases as you before extraction gets difficult. Soon as I have a hard time, I FL size the whole lot and start the process over again.

Anymore though, I find myself just FL sizing stuff all the time. Just seems to make things easier for me and I never personally noticed an accuracy benefit of just neck sizing and I'm not in a situation where neck sizing is advantagous to extending the life my brass.

 

[BGE541]

I always full lenght size magnum brass... Cant get more consistant then that. If you have a properly cut chamber you wont be overworking your brass either.

Just my .02

 

[Sniper Uncle]

I always F/L size my 338LM brass. I adjusted the dies to work the brass as little as possible---so the bolt "just" closes without resistance. There are many arguments for and against neck sizing, but I find it easier to resize each time, by as small a change as I can effect each time. It's just easier, in my opinion, and then I don't worry about the possibility of going to the range and having 2/3 of my brass fail to eject.

 

[Unknown]

The belts on belted magnum cases can change size with repeated firings and cause some of the issues you mention. If the belt thickens, or widens too much, the case doesn't fit into the chamber properly. Neck sizing only helps, but eventially, you might need to size the case. A friend of mine bought a collet die that squeezes the base of the case back down without changing the shoulder diameter, or setting the shoulder back. All his die does is squeeze the circumference of the case (belt included) back down.

 

[milo 2.0]

5 firings on any case, belted magnum or not, you're probably going to have to fl size. I've all but given up neck sizing, just bumping the shoulders enough to chamber. If you set your dies to bump the worst case brass, not all of them will be worked, or bumped, but still allow feeding-extraction.

 

[Deleted member 10043]

Unknown:

My Lee collet dies just neck size.

Collet Dies 300 H&h Mag - Lee Precision

What collet did your friend get?

 

[ksthomas]

Culpeper,

Ditch the Neck Sizing altogether, and just stick with F/L sizing for everything. You'll save yourself some potential problems (some possibly major, lots of minor ones) and will improve your accuarcy in the process. Stick with N/S for any length of time, and you will have some difficulties, usualkly at a time and place you can least afford it. I'd suggest investing in a bump gage or some other means of verifying shoulder bump back. Saves some seriuous problems down the road, guaranteed.

 

[Deleted member 10043]

Culpeper,

Ditch the Neck Sizing altogether, and just stick with F/L sizing for everything. You'll save yourself some potential problems (some possibly major, lots of minor ones) and will improve your accuarcy in the process. Stick with N/S for any length of time, and you will have some difficulties, usualkly at a time and place you can least afford it. I'd suggest investing in a bump gage or some other means of verifying shoulder bump back. Saves some seriuous problems down the road, guaranteed.

Wilco

Thanks for all the info, people. Muchas gracias.

 

[Sniper Uncle]

Culpeper,

Ditch the Neck Sizing altogether, and just stick with F/L sizing for everything. You'll save yourself some potential problems (some possibly major, lots of minor ones) and will improve your accuarcy in the process. Stick with N/S for any length of time, and you will have some difficulties, usualkly at a time and place you can least afford it. I'd suggest investing in a bump gage or some other means of verifying shoulder bump back. Saves some seriuous problems down the road, guaranteed.

Kevin, thanks for your input on this. I kinda had in the back of my mind that this would be the way to go, but it is good to have it confirmed by someone of your experience and "pedigree." I appreciate your advice. I did just purchase an F/L bushing die, and will adjust it to just allow smooth chambering--that should be about .002" bump---which should be the way to go, correct? Thanks

 

[TRTAC]

I always FL resize and do not think it harms accuracy at all. I use a redding with a neck bushing. Just size it to where it bumps the shoulder back .001 and adjust the die to only size about 3/4 of the neck. you will never have to worry about a stuck bolt again.

 

[ksthomas]

Sniper Uncle,

For a bolt gun, yes, .002" would be about as far as you'd want (or ever need) to bump the shoulder back. Culpeper's H&H is not really an exception here, but it is a bit of a different animal to deal with. The H&H cases have such a long, sloping shoulder due to their originally being loaded with cordite that they actually can make use of the belt. Headspacing off the shoulders with a more modern design (one with sharper shoulders and less body taper) is a lot easier. Still, you want to avoid headspacing off the belt as much as possible. I think the gages will be a big help here, but yeah, F/L sizing is the way to go.

 

[Deleted member 10043]

I found one. L.E. Wilson makes a case gauge for the .300 H&H.

 

[Sniper Uncle]

Sniper Uncle,

For a bolt gun, yes, .002" would be about as far as you'd want (or ever need) to bump the shoulder back. Culpeper's H&H is not really an exception here, but it is a bit of a different animal to deal with. The H&H cases have such a long, sloping shoulder due to their originally being loaded with cordite that they actually can make use of the belt. Headspacing off the shoulders with a more modern design (one with sharper shoulders and less body taper) is a lot easier. Still, you want to avoid headspacing off the belt as much as possible. I think the gages will be a big help here, but yeah, F/L sizing is the way to go.

Okay, Kevin, Thanks, I follow you now. I am not really familiar with the H&H's, although, now you mention it, I do remember reading they were belted cases.

 

[ksthomas]

They were actually some of the original belted cases, and it was a fairly ingenious solution to the headspacing problem at the time. What the designers were after was essentially a rim, that would still feed and function reliably through a bolt action's box magazine. The typical side-by-side double rifles generally use rimmed (or as the Brits call them, flanged) cartridges in these guns due to the ease in positive headspacing. Most of the British rounds of that period were loaded with cordite, long strand, double-based propellant in which each individual kernel was approximately as long as the combustion chamber of the case itself. In the H&H rounds (and no doubt several others), the cordite was added to the case BEFORE the necking operation. This is one of the main reasons they had such long, mildly tapered shoulders. Between this design feature, and the fact that production capabilities of that period wouldn't let them reliably headspace these cartridges on the shoulder, the belt made perfect sense. It is, in effect, a semi-rimmed design with the rim moved forward of the extractor groove. Despite the popular misconception, the belt adds nothing in the way of strength to a case. They do present some other problems for the handloader, but they became so synonymous with the term "Magnum," that it became nearly impossible to sell a cartridge dubbed as a magnum if it didn't have a belt. Thankfully, we seem to have moved past that point, and today we have several non-belted magnum designs that are becoming more and more popular.

Still, there's something truly classic about the H&H designs, and there is a bit of nostalgia rightly associated with them. Good performers all the way around, and the 375 is still the benchmark for big game performance throughout much of the world. The 300 H&H is the cartridge that bumped the 30-06 out of the winner's circle for long range competition, and it never did recover from that. Until quite recently, the larger 30 cal magnums held most of the long range records, and was the common choice for most competitors on the line.

 

[oldfatguy]

Going against the grain here. I use a Lee collet neck sizing die. Then a Redding body die every 4th or 5th firing. Biggest problem is the occasional stiff bolt closing when it is time to use the body die. Rounds have <0.002" runout and no lube to be cleaned off when neck sizing.

OFG

 

[ksthomas]

OFG,

To each his own, and so long as it's working for you, that's what matters. I guess I have a low tolerance for things like sticky bolt closures or extractions, but that's one of the reasons I prefer F/L sizing as a default position. Always seems like Murphy's watching, and waiting for that particularly inopportune moment.

 

[BuzzBoss915]

First of all, Kevin Thomas is a fund of knowledge. He's correct, of course, that the combination of the design of the 300H&H with the unfortunate decision to neck size these handloads is a recipe for problems. Depending on the "hotness" of the load, some type of failure to eject might easily have occurred much sooner. But, I have a question of the OP. Please clarify this part of your post for me:

"Today, nearly two-thirds of the neck sized cases did not extract when the bolt was pulled back. Subsequently, I did a full resize on the same lot and they all extract now."

Okay, extraction and ejection did not occur? So, what did you do, pound the bolt handle with a hammer, or use a cleaning rod down the bore, or what? What was the condition of the cases? Primer okay? Did you check case head expansion, any other signs of excessive pressure? Do you pay attention to brass flow and trim to length, which is important in a design having a long sloping shoulder: speaking as a person with extensive experience with a couple 220Swift's, same problem, semi rimmed, sloping shoulder, high operating pressures, etc.

Second, why did you continue to shoot these loads and deal with the difficulty of extraction? It seems to me that you should have stopped and evaluated the condition long before you accumulated two thirds of the total, however many we are talking about? Personally, my alarm bell goes off with the first (abnormal) event. I'm not judging, but you really need to pay attention to these warnings, way before you exhaust your supply.

Bottom line, get yourself a nice full length sizing die, (adjust it correctly) and sin no more. BB

 

[Deleted member 10043]

BuzzBoss:

No problem. 1. Used a cleaning rod and just tapped each case out and inspected them. 2. I continued shooting the entire lot (20 total cases) because I was shooting <.5 MOA 4 shot groups at 100 yards plus the cases showed no signs of failing other than they didn't extract and primers looked like normal spent primers (CCI 200 Large Rifle). Brass is by Hornady. This is a good rifle put together by Randy Selby who is in WY. The first time I shot this lot of brass I was getting <.25 MOA groups. I don't shoot a hot load. 67.6 grains H4831, 190 grain SMK, 2820 fps. I'm considering bringing it down to 2800 fps.

Still, there's something truly classic about the H&H designs, and there is a bit of nostalgia rightly associated with them. Good performers all the way around, and the 375 is still the benchmark for big game performance throughout much of the world. The 300 H&H is the cartridge that bumped the 30-06 out of the winner's circle for long range competition, and it never did recover from that. Until quite recently, the larger 30 cal magnums held most of the long range records, and was the common choice for most competitors on the line.

This is the reason why I have an H&H rifle. It is now a reloader cartridge. A few manufacturers provide preloaded ammo for hunting but I shoot it because of guys like Ben Comfort. It's a fun round, has about 100 fps lower expectations than the 300 Winchester Magnum but everybody has one of those. It's fun when an old guy looks at a spent casing and says I'm the second person he has ever seen shoot one of these in 60 years of shooting. The H&H slippery looking angles causes them to extract like the case has butter on it. That is, when it is extracting correctly... I'm learning as I go because I'm the only one I know about.

 

[BuzzBoss915]

It's just possible that your only problem is an extractor failure? Is this a M700 action or a Mauser type? BB

 

[Deleted member 10043]

M700 action.

Closer inspection of the brass shows the bolt cannot reach the extractor groove. It slightly gouged the OD of the rim. Headspace?

 

[BuzzBoss915]

if so, it could be related to neck sizing and failure to trim to length? BB

 

[Deleted member 10043]

Well, from what I understand thus far is repeated neck sizing resulted in too much head clearance between the bolt face and the head of the cartridge. I guess every time that I necked sized and spent the cartridge it increased the head clearance. Seems to be pretty uniform since the problem become material on nearly the entire lot at the same time and then after FL sizing they extracted with no problem. That is the unloaded brass after FL sizing. I wasn't completely loading then trying it out in the house. I came back from the range and tried the spent brass again with the same result as at the range. After that I FL sized the lot and then tried them again with no extraction problem. Based on my measurement it takes about .046" of excess head clearance to cause an extraction problem.

I've always checked COAL even with neck sizing. Max should be 3.60". I load between 3.58" - 3.59"

 

[Deleted member 10043]

It's just possible that your only problem is an extractor failure? Is this a M700 action or a Mauser type? BB

M700. I've kept this in the back of my mind since I read it. I took a brass rod and simply pushed on the extractor lip and the extractor separated at the rivet and rotated around the channel it sits in. Just looking at it I couldn't see that is was broke right there.