This is a 'for what it's worth' safety issue post. I was an armorer in the military and worked on gas operated systems. I own and shoot Garands on a regular basis and weigh in on the cautious side regarding ammo. One reason for that is the 80 plus pieces of brass particles that reside in my right arm as a result in a out of battery fire while trying commercial ammo several years ago. I took the word of people who didn't know what they were talking about.
So when a friend and neighbor asked me to check his old Rem 740 at the range because he was having trouble getting it on paper, I not only paid attention to his concern that it might be his scope, I considered other issues that might affect performance.
He has been shooting Remington 165 gr Core-Lokt and I took some of that with me on my first trip out. I also took some 'safe' ammo loaded specifically for gas operated systems. I fired 4 safe loads (lighter bullets-medium burn rate powder and CCI#34 primers) and noticed nothing about the cases to cause alarm bells to ring. After several rounds, I got the rifle on paper and shot a couple 1 inch groups (100 yds) with a Sierra 150 mk. First impression was that a 150sp might be good for a load for hunting although he is going Elk hunting and needs a heavier bullet.
Then I fired three rounds of his Rem 165 which spread out to over 2 inches. But the thing that caught my eye was the popped primers and the amount of gas blowby over the case body. And while PRE is but one of several variables to look at, expansion of .005 is greater than anything my Garands have produced.
I should mention that I put in about 7 hrs of technical study and forum reading on the 740/742/7400/750 and found that opinions range widely on the part of owners on the rifle and ammo used.
Well, I cleaned the rifle (bore only) and took it back out today with the S150mk thinking that the age of the rifle probably had a bearing on what it is doing but that head space could very well be the culprit. But, I am strongly inclined to believe that the rifle really is not intended for any and all ammo on the market.
At the second firing the rifle had lost its zero, badly, and my conclusion was that the cheap scope was the problem. However, the safety issue really convinced me to tell my friend to buy a new rifle or get his to a gunsmith. On this outing, the last 3 rounds popped the primers and had severe blowby.
One of the other things I did was write Remington and the company correctly informed me that popped primers were a reason to get the rifle to a Remington repair center. But they also wrote that since all of their ammo is mfg to SAAMI specs, it is all safe in their semi-autos.
Hogwash. A gas system will not tolerate fast/slow burning powders and the very heavy bullet loads will damage the gas system if not the shooter.
That was confirmed by Hornady and Federal, both companies writing to tell me that not all of their commercial ammo is suitable/safe for semi autos.
The last part of this long-winded story is that, oddly, the guy two benches from me today was shooting a Rem 740 30.06 among other rifles. He was sighting it for his grandson for a hunting trip. I asked him to let me look at his cases and when we examined the primers, about 50% were popped and there was substantial blowby on the case. He was startled and concerned that he had not paid attention before. He also commented that his grandson would be using a different rifle to hunt with.
The point I guess is that if you are shooting a favorite old semi auto, don't assume that any ammo is safe in it-that's not the case. And if you've seen any pressure signs whatever, do what Hornady recommends; 'Stop firing immediately'.
So when a friend and neighbor asked me to check his old Rem 740 at the range because he was having trouble getting it on paper, I not only paid attention to his concern that it might be his scope, I considered other issues that might affect performance.
He has been shooting Remington 165 gr Core-Lokt and I took some of that with me on my first trip out. I also took some 'safe' ammo loaded specifically for gas operated systems. I fired 4 safe loads (lighter bullets-medium burn rate powder and CCI#34 primers) and noticed nothing about the cases to cause alarm bells to ring. After several rounds, I got the rifle on paper and shot a couple 1 inch groups (100 yds) with a Sierra 150 mk. First impression was that a 150sp might be good for a load for hunting although he is going Elk hunting and needs a heavier bullet.
Then I fired three rounds of his Rem 165 which spread out to over 2 inches. But the thing that caught my eye was the popped primers and the amount of gas blowby over the case body. And while PRE is but one of several variables to look at, expansion of .005 is greater than anything my Garands have produced.
I should mention that I put in about 7 hrs of technical study and forum reading on the 740/742/7400/750 and found that opinions range widely on the part of owners on the rifle and ammo used.
Well, I cleaned the rifle (bore only) and took it back out today with the S150mk thinking that the age of the rifle probably had a bearing on what it is doing but that head space could very well be the culprit. But, I am strongly inclined to believe that the rifle really is not intended for any and all ammo on the market.
At the second firing the rifle had lost its zero, badly, and my conclusion was that the cheap scope was the problem. However, the safety issue really convinced me to tell my friend to buy a new rifle or get his to a gunsmith. On this outing, the last 3 rounds popped the primers and had severe blowby.
One of the other things I did was write Remington and the company correctly informed me that popped primers were a reason to get the rifle to a Remington repair center. But they also wrote that since all of their ammo is mfg to SAAMI specs, it is all safe in their semi-autos.
Hogwash. A gas system will not tolerate fast/slow burning powders and the very heavy bullet loads will damage the gas system if not the shooter.
That was confirmed by Hornady and Federal, both companies writing to tell me that not all of their commercial ammo is suitable/safe for semi autos.
The last part of this long-winded story is that, oddly, the guy two benches from me today was shooting a Rem 740 30.06 among other rifles. He was sighting it for his grandson for a hunting trip. I asked him to let me look at his cases and when we examined the primers, about 50% were popped and there was substantial blowby on the case. He was startled and concerned that he had not paid attention before. He also commented that his grandson would be using a different rifle to hunt with.
The point I guess is that if you are shooting a favorite old semi auto, don't assume that any ammo is safe in it-that's not the case. And if you've seen any pressure signs whatever, do what Hornady recommends; 'Stop firing immediately'.
