I was shooting a Win Mod 70 .300, and every time I shot it, the primers were flattening and the case (handloads, but new cases) showed signs of excess pressure, The same loads fired in my Browning, within minutes, showed none of these signs. The loads were the STARTING points listed in the Barnes manual, 165 gr xbt, 71 gr RL 19, Fed 210 primer, new brass. Additionally, the Win showed these signs with Federal factory rounds I had in my box. I fired a cartridge that had been reloaded twice and had head separation. I took as many measurements as I could, and could not figure out why I would find excess pressure in the Winchester. Any ideas?
Thanks for your help.
CE
__________________
"A hunter should not select a caliber and bullet that will kill when everything goes right, rather,
should choose ones that will kill when everything goes wrong."
"Recoil lasts a second, but gravity lasts forever."
Two comments here.....
1...head separation is typically the result of excess headspace and not excess pressure
2...it seems obvious there's something about the winchester that is elevating the pressures
something to consider...is the winchester barrel loaded up with copper fowling?....maybe there's another reason it's showing higher pressure But the excess headspace might be a clue.....sorry but that's all I can think of right now.
Excess headspace would cause the case to slam back into the bolt, flatning the primer, I have had this happen with loads that were too light and the case didn't expand enough, and the reason I dont pay much attention to the primer as a sign of pressure. Now if there are signs of escaping gasses around the primer or the primer pockets are loose on the next reload, then yes.
Head seperation is usually a good sign of excessive headspace.
__________________
A Computer lets you make more mistakes faster than any invention in human history--with the possible exception of handguns and tequila.
You should definetly have the headspqce checked. It may not be out of specs but it could very well be borderline going over.
I am not a big reloader but I get to test fire a lot of guns of many different makers and every time a rifle is borderline of blowing headspace, no matter the manufacturer, the primers are flat and the case gets the typical streched out ring around the webbing.
__________________
"The danger to America is not Barack Obama but a citizenry capable of entrusting a man like him with the Presidency........... Blaming the prince of the fools should not blind anyone to the vast confederacy of fools that made him their prince. The Republic can survive a Barack Obama, who is, after all, merely a fool. It is less likely to survive a multitude of fools such as those who made him their president."
I was shooting a Win Mod 70 .300, and every time I shot it, the primers were flattening and the case (handloads, but new cases) showed signs of excess pressure, The same loads fired in my Browning, within minutes, showed none of these signs. The loads were the STARTING points listed in the Barnes manual, 165 gr xbt, 71 gr RL 19, Fed 210 primer, new brass. Additionally, the Win showed these signs with Federal factory rounds I had in my box. I fired a cartridge that had been reloaded twice and had head separation. I took as many measurements as I could, and could not figure out why I would find excess pressure in the Winchester. Any ideas?
Thanks for your help.CE
Yes.
1. All guns are individuals. A load that is well below a maximum in one might be a lot over max. in the next one, even two with "identical" barrels that were chambered with the same reamer!! ALWAYS WORK UP A LOAD FROM BELOW FOR EVERY DIFFERENT GUN!!
2. Head separations come from excessive resizing - you're pushing the case shoulders too far back when you size the cases. Back your sizing die out so that it only sizes down about 2/3rds of the case neck, and this will stop! This happens a lot with belted magnums, many of which have overlong head-to-shoulder distances, which manufactureres don't seem too concerned about, because belted magnums are DESIGNED to headspace on the belt, not the shoulder!!
ktsContender said:
Quote:
Head seperation is usually a good sign of excessive headspace
And he's right! BUT what both folks that mentioned excessive headspace failed to tell you is that it's not the RIFLE that has a problem! You're creating the excessive headspace when you size your cases by pushing the shoulders back too much. See above!!
Toro Grande said:
Quote:
You should definetly have the headspqce checked. It may not be out of specs but it could very well be borderline going over.
Mooooo!
__________________
"Bitte, trinks du das Wasser nicht. Dahin haben die Kuhen gesheissen."
Ditto to what eldeguello said. I neck size only on my 7 mm and 300 mags. Before I started doing that I had a head separation. Took the rifle to a 'smith, left it there, and two days later the place burned down. Lost the weapon (and the insurance never covered it).
__________________
Never trust a bow under 40 (inches).
ALWAYS WORK UP A LOAD FROM BELOW FOR EVERY DIFFERENT GUN!!
I believe that he said that this was a STARTING load. How far below the starting load should he go? Make sure that he doesn't go too far below so he doesn't blow up his gun with too little powder.
Quote:
The loads were the STARTING points listed in the Barnes manual, 165 gr xbt, 71 gr RL 19, Fed 210 primer, new brass.
Quote:
You're creating the excessive headspace when you size your cases by pushing the shoulders back too much.
He stated in the original question that this was NEW brass. Why would he need to resize NEW brass unless a specific case just happend to be out of specs? Which he said he did and stated that he found nothing wrong.
You don't think that Winchester could ream out a barrel just a little too far and the barrel have excessive headspace? If he is getting badly flattened primers, and severe case strech with starting loads and ammo that is within SAAMI specs then something with the barrel is most likley the culprit. The starting point would be to check the headspace the next step would be to pour a chamber cast to make sure that the rest of the chamber is within specs.
Quote:
This happens a lot with belted magnums, many of which have overlong head-to-shoulder distances, which manufactureres don't seem too concerned about, because belted magnums are DESIGNED to headspace on the belt, not the shoulder!!
Regardless if the case has a belt or not the overall chamber has to be within specific tolerences. Gun manufacturers don't just make a chamber to what ever size they want so long as the belt fits. That would be completely absurd not to mention very dangerous.
So MOOOOOOOOOOO!!!!!!!!! Right back at ya and please don't isnult my intelligence. Thank you.
__________________
"The danger to America is not Barack Obama but a citizenry capable of entrusting a man like him with the Presidency........... Blaming the prince of the fools should not blind anyone to the vast confederacy of fools that made him their prince. The Republic can survive a Barack Obama, who is, after all, merely a fool. It is less likely to survive a multitude of fools such as those who made him their president."
BUT what both folks that mentioned excessive headspace failed to tell you is that it's not the RIFLE that has a problem! You're creating the excessive headspace when you size your cases by pushing the shoulders back too much.
This simply is just not true.....A properly made die that has not been altered will only force the shoulder to the proper headspace dimension per SAAMI specs for the cartridge upon full length resizing.....unless the die was incorrectly made at the factory, the die has been ground off at the entrance end or the shell holder has been ground off for some reason.
One cannot cause excess headspace by reloading but if the rifle does have excess headspace a savvy reloader can compensate by "backing off" the die to not return the shoulder to the original length. In a sense it's a case of two "wrongs" can make a "right" and works well in most cases.
The best solution is always to cut off a thread on the barrel and rechamber to correct headspace.
One cannot cause excess headspace by reloading WRONG!!! but if the rifle does have excess headspace a savvy reloader can compensate by "backing off" the die to not return the shoulder to the original length. In a sense it's a case of two "wrongs" can make a "right" and works well in most cases.
Vapo, if you are talking about beltless, rimless cases, what you say is pretty close to being true, but there can be exceptions!! I have seen cases in which dies were as little short in the head-to-shoulder dimension, and you cannot ASSUME that a die is made right until you check it to make sure!! Just screwing it down to where it solidly contacts the shellholder, like the instructions invariably say you should do, can cause problems.
However, belted cases headspace on the belt, as I assume you know, and a great number of belted magnum chambers have come from manufacturers over the years THAT DID NOT HAVE EXCESSIVE HEADSPACE, BUT STILL PERMITTED CASE SHOULDERS TO MOVE FORWARD TOO FAR on firing! Reloaders often made the mistake of screwing their die down to contact with the shellholder, set shoulers back during FL sizing. This causes excessive working of the brass and resultant insipient head separations!! Many a magnum shooter has learned this lesson the hard way. With very short case life.
__________________
"Bitte, trinks du das Wasser nicht. Dahin haben die Kuhen gesheissen."
Excess Pressure???
