backed out primer's

[flyingstick]

My .303 british is backing out the primer's now. I've been loading with Steve's cast recomendations from the .303 british website. Started with 17 grns of Reloder 7 up to 24 grns, filled to the bottom of the bullet with COW.
I've read serveral threads recomending powders that fill the case. What type of powder would come close to filling the case of the .303 and still be usable for the 185 grn. cast boolit?

[NVcurmudgeon]

Does your .303 back out the primers with factory loads or factory level handloads, or is it just with your cast loads? If it happens with only cast loads, sounds like pressure too low. Backed out primers with full power loads can be an indication of excessive headspace. If you want moderate velocity loads you could try a faster burning powder. I use 16.0 gr. of 2400 (1500 fps) with a 200 gr. Lyman 314299, and 9.0 gr. of Green Dot (1100 fps) with a 170 gr. Lyman 311413. Primers are rounded, looking like pressure was low, but not backed out. I haven't tried Reloader 7 in my 1943 Fazakerly No. 4, but your loads sound low. Lyman or Lee loading manuals have plenty of good .303 loads, and I am sure you will hear from other board members about what has been successful for them.

[flyingstick]

Thanks for the information. And, No sir it has never backed out primers before. Not with any other handloads, factory ammo or surplus.

[45 2.1]

The COW probably is the cause. Some fillers, when too much is used or over a certain volume in the case, cause the upper case walls to grab the chamber and won't allow the case to slid back. I would adjust the load so you don't have to use the COW.

[grouch]

Just maybe if you're full length sizing, it is a headspace issue that only appears because of the low pressure. If that's the case, neck sizing so that you headspace on the shoulders should improve the situation as well as dramatically improve case life.

[fourarmed]

Since it is a rimmed case, I would guess that your rifle's headspace is a little excessive for the rim thickness of the cases you are using. I had a similar situation with a 7mm Int-R pistol. It never led to any problems, so I eventually quit worrying about it.

[cbrick]

Since it is a rimmed case, I would guess that your rifle's headspace is a little excessive for the rim thickness of the cases you are using. I had a similar situation with a 7mm Int-R pistol. It never led to any problems, so I eventually quit worrying about it.

If the brass is sized after each firing to just move the shoulder back and thus creating an excessive headspace situation (even with rimmed brass) the problem that will develop is short case life. If the shoulder is moved even further back case failure can occur.

With brass fired in your chamber smoke the shoulder and neck, set the size die (either NK or FL) to where you can see that the shoulder is barely touched but not moved. Test this round in your chamber to make sure the action closes properly. If resistance of the un-loaded, chambered case is felt adjust the size down very slightly and chamber it again. Do this until the sized case "just" fits the chamber and then lock the die down and headspace should be correct for that firearm.

If your shooting a bolt action firearm once the brass is sized in this manner the case should not grow in length from the case head to the datum line on the shoulder. If your shooting a break open action such as the T/C where it is known that the frame stretches with each shot it is probable that the shoulder will need to be bumped back a touch when re-sizing.

If you suspect the firearm has excess headspace try firing virgin brass with the bullet seated to touch the lands. Then when reloading this brass adjust the size die as mentioned above. If you are shooting cast seating into the rifling shouldn't boost pressure enough to notice. If your shooting condom bullets with a near max load it should be backed off a bit.

Setting the shoulder back can shorten brass life as well as cause primers to extrude. Light loads as well can cause primers to extrude. 30 or 40 years ago Speer did a lot of testing with light loads for this very reason.

I have never used fillers as was mentioned in this thread so I can't comment on the effect of that on the primer.

Rick

[flyingstick]

Thanks folks, I went back and looked at the brass, and the only primers that backed out were the 17 grn loads. It was new brass. I'm loading up some more now so we will see how it goes.
Thanks again.

[leftiye]

Neck size only. Headspace on the shoulder.

[PPpastordon]

flyingstick;
First of all, if the primers are setting back the pressure is very low. This can be demonstrated by firing a case with only a primer in it. The primer will almost always back out of the case.
It may be too early to neck size only. How far are the primers protruding from the case? Do you want your brass to stretch that much, or more? If not, expand the case neck using a larger caliber neck expanding die to a size that WILL NOT FIT INTO THE CHAMBER. A .338 expanding plug placed into a .35 Remington die should work.
Next, neck size the case with a .303 die - only until the case will just barely fit into the chamber. Then reload as usual, without further sizing, and with a load close enough to normal to expand the case to the shape/dimensions of the chamber. This is called fire forming and has been used by "Wildcatters" for many years.
Otherwise, stretch the body of your case by just loading it to a proper pressure; it may make little difference in case life. However, if the amount of stretching is too much it can/will lead to early case failure; possibly through case head separation. That could lead to an undesired event with damage to the weapon and (possibly) damage or worse to you. Good Luck!

PPpastordon
"You cannot spell 'Good' without 'God.'"

[fourarmed]

cbrick's description is correct if the cases are of normal length. Yours are too short to the shoulder already, and no amount of sizing will increase that. Pastordon's advice will lengthen the case to proper chamber length if used with something approaching a full power load. The problem is, the cases will shorten right back using very light loads unless you open up the flash holes. This was discussed in another thread recently. As I mentioned in my earlier post, I had a similar situation with a load that suited my purpose - light recoil for silhouette shooting from the standing position - and I used those cases for that load for several years with no problems.

[cbrick]

The method I described is the one used most often by fire forming the TCU cartridges from the parent case 223 Rem. The 223 is a rimless case and headspaces on the shoulder, the shoulder of the parent case is further back than the formed 7mm TCU. By seating the bullet against the lands so that the case head is held against the breech face the shoulder is blown forward and out. Its not the sizing that properly headspaces the cartridge on the shoulder, its the fire forming. After fire forming proper sizing as I described in the earlier post is needed to maintain proper headspace. Full power loads aren't needed and reduced loads seem to work as well as full power loads.

The only draw back to this method that I am aware of is too little case NK tension, i.e. case lube inside the NK, allowing the firing pin to drive the case forward thus seating the bullet deeper before pressure forms the shoulder in the proper place.

I have never tried the other method described but I can't see any reason it wouldn't work. The only drawbacks to it that I can see is further working the brass and additional dies needed.

Rick

EDIT:
fourarmed, you mentioned silhouette, ask some of the guys at your club how they form their 7 TCU brass. It would be interesting to compare different methods used around the country.

[fourarmed]

Rick, I got this method from one of the Techs at Sierra, who is the Missouri IHMSA director. He loads the .223 cases with around 4 or 5 grains of Red Dot, Bullseye, 700X, or the like, then fills the case with COW and tops it with a drop of Elmer's Glue. He lets them sit overnight, then fires them. (He claims it is an excellent way to prune weeds along the sidewalk.) He specifically warned against letting them go longer than overnight, as he says he has shot off case necks if the glue has too long to harden.

In addition to opening the flash holes, I have read of lightly lubricating the case in light-load situations. I am aware that this is normally a big no-no, and one would certainly want to dry the chamber thoroughly before firing full-power loads.

I have always heard that the false-shoulder method is preferable to the jammed-bullet method, but have no firsthand knowledge.

[45 2.1]

[quote=fourarmed;139312]In addition to opening the flash holes, I have read of lightly lubricating the case in light-load situations. I am aware that this is normally a big no-no, and one would certainly want to dry the chamber thoroughly before firing full-power loads.[quote]

Roy Weatherby fireformed his 220 Rocket cases for sale this way, and not with too light of loads either. It works fine if you know what your doing. In addition, George Nonte used furniture wax sprayed on loaded cast boolit loads to get some of the military semi-autos to function correctly.