Turn old into new

[gene pool]

Where is 8ball? He was going to shoot the rifle with the clogged barrel on Friday. I hope his absence of report doesn't mean something bad happened to him.

 

[subsonic]

8ball is still here, i got very busy after i when to the range and as old age sometimes gets the best of us I forgot my password. The gun operated fine, accuracy my have been ok if not for me chasing the X using a bad scope that would not hold POA (elevation). One thing I did notice was after each round was fired the cartridge case had soot or powder burns covering the outside of the case, almost back to the rim. Is this an indication of using the reduced load or a problem in the chamber? When I spoke to a gunsmith in my area, who was fresh out of gunsmithing school in Colorado and under 25 years old, he responded that was impossible and when I asked about re-barreling with a 1:12 or 1:13 twist barrel he replied no one makes such a barrel and I could only get a 1:10 twist for a 308WIN. So I ran from this place as fast as I could.

 

[spclark]

Yes, the dirty cases are most likely from the reduced loads: case necks don't seal the chamber under lower pressures so you get some gas leakage backwards.

As for that new smith, he obviously has a great deal more to learn... I hope nobody gets hurt as a result of his having slept thru class.

 

[subsonic]

spclark, thanks for clarification. If I continue to shoot the reduced loads do you think it will be worth having a custom reamer made to make a tighter chamber to reduce the blowback or fire a bunch of full load rounds and neck size only?

 

[Tozguy]

While waiting for SP's reply, I would just like to suggest that you take the load up gradually instead of going to max right away. Also, let us know how much of which powder you used so far. Chances are the dirty case problem can be solved with the right powder and load.
The tighter reamer option involves a considerable expense. I personally would question spending that much on that old barrel of yours (or were you referring to a new barrel?) to fix the fouling problem. Either way, loads that are too light will likely foul up any size of chamber.

 

[spclark]

Agreed - you may not need much more powder to get a better neck seal. MUCH less costly than a new reamer, plus a new barrel blank to use it on, plus a smith's fees to do the work (unless you're equipped to do the work yourself) just to get cleaner cases... out of a rifle that's not used for competition.

First try bumping the charge up a little, or using more neck tension, or even a different propellant choice.

It's also possible your barrel's worn or out of spec & the bullets you're using aren't holding the pressure where it belongs too. This is where "slugging" the bore can be of help. You might need to go with cast lead bullets, perhaps slightly oversize or even fitted with gas checks... but again, this isn't a target rifle so how much time & money you want to spend on getting "acceptable" results is strictly up to you.

Give us some info on what you're using now, maybe we can help steer you to a combo that works better.

Above all else, use caution when reloading for and shooting this rifle.

 

[subsonic]

hey guys thanks, I'm using 29.5gr H4895, 200 CCI primers, 135gr SMK and Remington brass. After measuring a full length sized loaded cartridge I have 0.336 @ neck, 0.450 @ base of the shoulder and 0.466 about 0.325" above the rim. The fired case measures 0.336 @ the neck, 0.457 @ base of shoulder and 0.466 @ 0.325" above the rim.

As far as the cost of re-barreling and the reamer my wife says it's okay and she doesn't shoot. I was speculating that given the age of the gun and the fact that the gun was used for hunting and not cared for properly the barrel may be worn.

 

[spclark]

How did you arrive at that load charge weight?

Looking at Hodgdon's data page (they dont show a 135 SMK so I'm looking at a Speer 130 just to get close) your load is well below their suggested minimum of 45 grains. For a 155 Sierra HPBT it's 43 grains.

You mentioned a recipe for reduced loads you got from Hodgdon; can you post a link where that can be found? Their general instructions are to start 10% off maximum loads where no specific load info is given. That would put you somewhere around 45 grains, 49 being their maximum for a 130.

In your rifle you might even want to start a little lower yet, say 40 grains?

Loads that are too far below suggested minimums can be dangerous too as the propellants can vaporize then combust explosively rather than burn at a more controlled rate. From your case measurements that doesn't sound like it's happening but I still suggest you need another 9 or 10 grains of H4895....

Do you have any rifle cartridge reloading manuals on hand? If not there's plenty info out there on the net but even at that using some suggested loads you need to be aware of the limitations of your rifle! What's safe in mine most assuredly might be downright dangerous in yours!

 

[subsonic]

spclark, when you are on Hodgdon's home page, look under "Data" you will see "H4895 reduced rifle loads". This is where I found the formula for my load, maximum load X 60%. I used the data from the 130gr SPR HP max load of 49.0C for my starting point as with there formula for a safe reduced load (49.0gr x 60% = 29.4gr) as stated in the second paragraph. Yes I do have a couple of manual, it was suggested to me to use Hodgdon's site for reduced loads as a place to start.

 

[spclark]

OK, that's data I'd not seen before I admit and I thank you for turning my head to it today.

In the table on that page they provide a load for the Sierra 135 soft point, close enough to their 135 SMK at the pressure shown, for 308 WIN w/24" barrel of 36.5 grains H4895, which ought still to be safe and provide enough pressure to seal your case necks.

If the only problem you still have after all your time & trouble bringing this rifle back to life is sooty cases, I think you've done a fine job!

(Another risk of very low charges in rifle cases is that when the rifle with a cartridge in the chamber is pointed downward before discharge the propellant may all be up at the front of the case when the rifle's raised up to horizontal. It may not ignite properly yet the pressure from the fired primer pushes the bullet into the bore, where it stops. When using reduced loads of this nature be very sensitive to the consistency of the sound produced when fired....)

 

[wapiti25]

I would go up in the powder charge. Some reduced loads use a heavyier bullet. If you want to rebarrel contact E.R. Shaw, their barrels will usually shoot 1MOA or better and they are the cheapest. They do the fitting or used to, I have not checked on them for years. Good luck

 

[subsonic]

thanks gentlemen, I will try a heavier bullet and also try the recipe Hodgdon listed for the 135gr Sie reduced load. I will post again my findings after I visit the range again. Thanks again for all your comments.