Various Questions:

[Dinky]

First, I would like to introduce myself and thank the moderators and old-timers on this board for the opportunity to participate and benefit from your expertise. With me, please assume no knowledge--when I ask for advice, I do not shoot the messenger!


I reloaded, in a very basic way, for a number of years, up until about 1985. Then, about 5 years ago, while I still made pretty good money prior to retirement, I had two custom hunting rifles built, both on 700 actions, blueprinted, with Lilja barrels, and the whole nine yards. The first rifle is a 5 1/2 pound little Mountain rifle, in 300 Winnie, with 23 inch barrel and muzzle brake and a Swarovski 3-10x42 with the BR reticle. So far, I have only used this rifle with factory ammo on dog-sized Texas whitetails. The second, its big brother, so to speak, weighs about 10 pounds without a scope, and is chambered in 300 RUM, with a 27 inch medium heavy barrel, muzzle brake, and Swarovski 3-12X50 with TDS Plex reticle.


At the same time, I bought all the stuff for reloading, someday, with Rockchucker press and mainly Sinclair and Wilson tools--including pretty much all the tools to ensure maximum accuracy. At the time, (genius that I am), I figured I would be able to obtain 300 Winchester brass anytime so I only bought 100 rounds and I recently found 5 pounds of RL22. For the big rifle, I had the foresight to stock up on 600 rounds of Remington brass, several thousand primers (for both rifles), and 15 pounds of RL25.

I am now working my way through the research and reloading process. I would like to discuss only the 300 RUM at this point and pose some questions: To date, I have inspected and weighed 100 rounds of the RUM brass, de-burred the flash holes, and uniformed primer pockets. I was pleasantly surprised that all 100 cases came within .6 percent plus/minus of the average weight of 268.8 grains. Although I have read you should be closer than that for BR, I am thinking for even long-range big game hunting, I should be OK.


I have ordered some factory ammo so I can fire several rounds to get an idea of what the chamber looks like as far as headspace goes. (I have the RCBS Precision Mic tools for both rifles.) My plan is to wait until I can measure these before setting up my die for resizing. This rifle was chambered somewhat tight, (which I understand is not uncommon with custom 300 RUM rifles). So the builder recommended I purchase the small-based Redding resizing die. I did and plan to use that. I also plan to turn necks, using the Sinclair tool preceded by use of the corresponding expander body/arbor.


Question # 1: My thinking is that I should FIRST, run the cases through the expander body/arbor, followed by turning the necks, and THEN do the full-length resizing in the small based die, having removed the expander ball (in order to avoid over-working the neck). Do you agree with this order of battle?


Question # 2: IF the answer to the above question is "yes", will the expansion due to the expander die be sufficient to seat a bullet with proper neck tension without benefit of having had the expander on the sizing die run through the neck?


Question # 3: (Think like a hunter here), would you recommend continuing to use the full-length, small based sizing die on each subsequent reload of the case OR will it be likely enough just to neck size and then run each round into the chamber to make sure it will fit?


I assure you, I will have other questions in the future and thank you in advance for you help.

 

[FearNoWind]

1. Yes, I would do it in that order to ensure that all of your necks are the same dimension when they are turned. They sometimes come out of the factory with different neck sizing.

2. For the first firing it should not be a factor. For subsequent loading cycles it will of course depend on the neck sizing die you use and the diameter of the mandrel; assuming that you run the sizing die over the necks before running them over the mandrel. I usually do the neck sizing and follow with the mandrel to ensure even neck tension. Even wall thickness, even neck sizing, equals even neck tension.

3. There are several schools of thought on this subject. Fire forming cases and then only setting the shoulder back and neck sizing seems to work in some rifles but most of mine want full resized cases. Frankly, I find it easier to full length resize than to try running cases through the action to see if the fit than to spend the time with that trial and error method because I understand that if they're not a good fit I have to resize them anyway and then I have brass with different body sizes - not a good thing.

 

[Dinky]

Thanks, Fearnowind. I went ahead and ran my first two batches of 50 Remington cases through the expander die in preparation for neck turning. I made what I now know to be the stupid mistake of trying to guide the first round up into the mandrel with my fingers--resulting in a horribly deformed case mouth. After I figured that out, everything went smoothly.

So now I will turn the necks but will wait to run the cases through the small based dies until
I can fire some factory ammo to obtain headspace information on my chamber with which to set the sizing die.

Dinky

 

[AZShooter]

I want to offer a few suggestions which I hope will help you. I have been handloading for over 30 years. In the beginning I made many mistakes which cost me money as I ruined my share of brass due to ignorance. I don't know how much you know and offer the following suggestions on what I read in your first post. Please ask questions if I am not lucid enough.

QUESTION 1:

You didn't mention the rifle's chamber neck dimension. I understand that you are tying to make all cases have very similar neck tension by turning the necks, it is just that you may end up shortening the brass life if the chamber's neck dimension is generous. You will then have to reduce the diameter of a fired case's neck to hold a bullet possibly overworking the brass. Turning the necks may shorten the life of the brass.

I suggest you find out what the chamber neck dimension is from the gunsmith. Then measure the outside diameter of a loaded unturned piece of brass to determine if you have sufficient clearance for bullet release. I will bet you do. It is good to KNOW.

Factory brass is usually sized smaller than what you can do with a standard FL sizer die. I see no reason for you to run the virgin brass through the small base die. I wouldn't use the small base die unless I couldn't get the brass to fit properly after trying to size FIRED brass with the standard FL die. Small base dies are usually used for auto loading rifles to ensure they chamber with no resistance. IMO it is a very rare bolt action rifle that needs a small base die.



If you do turn the necks then run the brass into either a standard FL or a small base FL die without a sizer ball you may or may not get you the neck tension you need. I would say the resultant neck tension you will get without a sizer ball will be too much perhaps in the order of .005" or more!

Most FL dies reduce the neck diameter more than necessary then rely on the sizer ball to open up the inside diameter so you end up with proper neck tension. The reason for this method is to be able to size different brands/wall thickness brass. It is possible to turn the necks quite a bit and use a FL sizer without a ball and end up with a useable neck tension but those necks will be very thin. Shoot them in anything but a tight necked chamber and you will split the necks on the first firing. I know because in my early years of shooting I did it.


I reread your first post and am not sure if you have a bushing die. If you turn your necks you will be better served using one to get the neck tension you require. As for sizing the body a separate Redding body die will size the body and shoulder independently from the necks.

Or you can skip the neck turning and use the standard FL die to get the necks ready for loading. You might be pleasantly surprised when your rifle shoots good groups without neck turning. I use a custom reamer for my 300 RUM and I use the RCBS FL die and it shoots fine with unturned Rem brass.

QUESTION 2:

I would say the expander iron used for neck turning will not get you the proper neck diameter for good bullet grip/neck tension. BR guys sometimes use the expander iron as part of the soft seating method something you won't want to use for a hunting rifle. Recoil will very easily move the bullet in the case.

QUESTION 3:

Like I suggested earlier don't use the small base die unless there is a need for it. A properly setup FL die or a body die can size the body and shoulders just enough for the fit you desire. Most hunters like a fit that doesn't require any effort to close the bolt. The adjustment of the die determines this fit. Just don't over size past this adjustment.

Whatever you do don't just set up the FL die or body bump die to kiss the shell holder when you start to size the brass. Instead set the die away from the shell holder size a piece of fired brass and see how it fits the chamber. Progressively adjust the die closer to the shellholder until you get the fit you desire.

 

[Dinky]

Thanks, Arizona! I will digest your very thorough reply and will no doubt have some questions. One quick one: in order to ascertain the neck dimension of the chamber, can I just fire a few rounds and then mike the necks and take the average--or does the brass in the neck spring back enough to invalidate that technique?

 

[AZShooter]

There is spring back. Best way to get the chamber neck dimension is to ask the gunsmith who used the reamer to chamber your barrel.

 

[Dinky]

OK, I plan to call the gunsmith tomorrow re neck dimensions. Should I also ask about any other chamber dimensions?

In the mean time, I have made the decision not to neck turn my first batch of reloads. I bought a tubing mike along with all the other stuff I never managed to try out until now. after fiddle-farting around with it for an hour or so, I have concluded that I would rather be burned at the stake than use it! Until I can either afford a Sinclair digital case neck micrometer, I am either going to skip turning altogether or turn everything in a batch.

Comments welcome!

 

[AZShooter]

If you can get the print of the reamer. It is nice to know.

An easy way to figure out the neck wall thickness is to measure the OD of the a loaded round and subtract the diameter of the bullet then divide by two.

Feel free to ask questions anytime.

 

[FearNoWind]

OK, Dinky, looks like you're on the right track. I think what AZShooter suggested is real good stuff.
Sorry I forgot to suggest consulting the builder about the reamer. Might also be a good idea too ask how many times the reamer has been used to consider whether it still meets original specs. - they do tend to wear a bit over time and for most shooters .0005 is a lot of room when doubled for chamber diameter. A casting of your chamber would probably be the most accurate test.
However, quite frankly, even the most finicky bench rest guys don't usually get too nervous about .005 neck wall thickness affecting neck tension as long as their neck clearance within the chamber is also within those limits of tolerance.

 

[Dinky]

Thanks, guys. There probably won't be that much info available about the reamer as it has been several years now. I am going to look into taking a cast of the chamber.

 

[Unofficial Gun Addict (UGA)]

I just thought I would pass on some advice I received here that has given me good results. I used to FL size my 300wm every time I reloaded them. I found that my brass life was relatively short. A couple of experienced reloaders suggested that I purchase the lee collet neck die and only fl resize every 3rd or 4th time I reload, depending on what I was seeing with respect to my cases.

I took their advice and have found that my accuracy improved as well as case life. I then bought another for my 308 with similar results. I believe youtube has a couple if good videos about them which also helped me to make up my mind prior to buying the first one.

I like that the mandrel inside the collet die matches the diameter of the neck size I want, and that if you want more tension, all you have to do is get some flitz polish, pull out the Dremel, and polish it down to the size you want (keeping spring back in mind). Also... No lube required is a big plus.

Good luck and it sounds like you've got some good advice already!

James

 

[AZShooter]

Take micrometer or dial caliper in hand and visit the gunsmith. Measure the neck diameter of the reamer. Or have him do it. No reason why you cannot get that measurement.

 

[Dinky]

Well, I called my gunsmith. A few remarks about him may be in order: First, he is world-renowned and builds really great rifles. But let's just say that being a "people person" is not one of his great strengths. He told me under no circumstances would he recommend neck turning for either of my rifles..."...not with the chambers I use." I asked if that was because they were large enough that taking away brass would cause the necks to split early. He really didn't answer that but instead said: "Why would you want to turn them? It wouldn't do you any good!" I never even got to asking about a reamer print. I did ask him if he recommended neck-sizing only for either rifle and again, he said "no" but to use FL every time for the .300 Winchester and small-based every time for the 300 RUM. He kept emphasizing that I would be using them for hunting and not bench rest.


So I guess I am intimidated by my gunsmith! Go figure. In my life, I have cross-examined some pretty evil people on the witness stand and negotiated with folks you wouldn't want in your backyard--much less your living room--but I always dread calling the guy I paid mucho dinero to to build my rifles, and then can't wait to get off the phone. Sheesh. In any case, I think I now understand the principles and whys and wherefores of neck turning pretty well--especially with yall's help. Here is what I am hearing between the lines from my gunsmith: like most hunting rifles, he builds his with considerable clearance for the neck--in order that they will chamber just about everything.


When I am able to find someone in South Texas to do it, I will have a chamber cast made. (I am one of those folks who has difficulty hanging a bird-feeder in a tree.) In the meantime, I am going to take the 'smith's advice--full length and small-based resize for the two calibers, then check for accuracy and velocity with the same loads he used and documented. Although he said nothing about this, I am going to check five rounds each of factory brass fired in each rifle for headspace and length and then bump the shoulder back 2-3 thousandths smaller than the readings I get from the RCBS Precision Mics.



When I take those readings with the mics, I may be back in either this or another thread, seeking advice on what I find and verifying what I plan to do with the findings.


Thanks again to all and don't hesitate to weigh in!


Dinky

 

[Dinky]

Reviving this thread with an update: I won't bore anyone with the details of my relationship with my gunsmith--suffice it to say that he is an outstanding gunsmith, but not what one would call a "People Person". I never even got to the question about a reamer print--and I won't. Nuff said.

Here is my plan, subject to anyone telling me I am a complete idiot--something I have not heard since I had to quit drinking and therefore making a fool out of myself in bars in the mid-'eighties:

1. I calipered five fired cases in each of my two custom rifles--measurements averaged .342 in the 300 RUM and .341 in the 300 Winnie. Adding a thousandth for spring back yields an estimated chamber neck diameter of .343 in the big gun and.342 in the little guy. The necks of five loaded rounds for each caliber averaged .340 in the RUM and anywhere from .335 to .338 in various factory brands of the Winchester. Thus, I would seem to have a neck clearance of only about .003 in the 300 RUM whereas there appears to be anywhere from .004 to .007 in the 300 Win, depending on which brand of factory ammo I measure.

So I am thinking I might be justified in just cleaning up the outside of the necks a little--say just enough to reduce the overall neck clearance by a thousandth or so. I may try this with one batch of cases and leave the other batch un-turned. Would any of you hesitate hike off into the inaccessible wilderness where there are no gun smiths to hunt with only 3 thousandths overall neck clearance?

Thanks to all.