Bullet Seating Depth
I am starting to load 7mm Rem Mag. I'm new to metalic loading as I've stated in other questions ,so take it easy. I used a spent case(dud primer and no powder for safety) and a bullet seated "losely" and I chambered it in my gun a few times to get an idea of my chamber size.(I pulled it out long each time I chambered so it would compress to chamber size) I got a consistant 3.425". I was on the phone today with tech's from Hornady and Hodgdon(I'm using 162gr Hornady's and H1000) and one told me that the 3.290" COL for 7mm rem mag wasn't always the "rule" for length. He said he seated his 7mm rem mag .020" of the lands in his 1962 Model 700(which he thought was ~3.390"). He also told me he did this because his gun lost a lot of gas between the cartridge and throat because of the gap, which equals less FPS. He said he could load in his specific gun 5grs more in a Win. case because he seated out further and it left a larger cavity in the case for the powder(cheaking for pressure signs.)My COL would be ~3.405" which is well over the standard 3.290" that I think most factory ammo with ~160gr bullets are used. I did notice that the smaller bullet weights had a seating depth of 3.150"- 3.250" because they aren't as long, and I understand I probly won't be able to seat them all the way out to the .020" off the lands. What do you all think about his information on the COL and .020 off the lands?
F.Y.I. Remington Model 770
3.405" leaves me .035" room in magazine.
F.Y.I. Remington Model 770
3.405" leaves me .035" room in magazine.
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Testing variables in 22 to 35 mph winds is impossible. Don't draw any conclusions on these results. Some observations : Many times faster bullets hit lower. It's probably barrel harmonics. Reread Rocky's comments. Loading closer to the lands increases pressure but can result in lower velocity. Testing in good conditions and changing only one variable at a time is paramount to improvement. If your barrel is new, you should clean every 5 shots or so. It is slower but effective to achieve best results. 0 -
Thanks, but I still have one thing in mind.
It's a Remington Model 770.Expecting it to shoot is like sitting on an egg hoping for a gold nuget. BUT, stranger things have happened[:p]0 -
Buy the sinclair seating depth tool, and the sinclair comparator. THAT will give you all the info you need, clean up to benchrest competion. read the directions and you will understand how the pair of these tools will give you all the info you need as far as seating depth is concerned.
These are what I use for everything from factory rifles, up to my Benchrest and longrange rifles. You can run the test the same way, a hundred times over, and still get the same measurements, right down to the .001"
The best part about the sinclair tool, is that it specifies the use of a FIRED CASE FROM YOUR CHAMBER. That is the key to getting it right. The LEE tool won't be on par with anything made by Sinclair. Their staff is made up of longrange and benchrest shooters. I have had many long conversations with their employees before buying a tool and I can say, those boys know their business.0 -
quote:Originally posted by JustC
Buy the sinclair seating depth tool, and the sinclair comparator. THAT will give you all the info you need, clean up to benchrest competion. read the directions and you will understand how the pair of these tools will give you all the info you need as far as seating depth is concerned.
These are what I use for everything from factory rifles, up to my Benchrest and longrange rifles. You can run the test the same way, a hundred times over, and still get the same measurements, right down to the .001"
The best part about the sinclair tool, is that it specifies the use of a FIRED CASE FROM YOUR CHAMBER. That is the key to getting it right. The LEE tool won't be on par with anything made by Sinclair. Their staff is made up of longrange and benchrest shooters. I have had many long conversations with their employees before buying a tool and I can say, those boys know their business.
AMEN[;)]0 -
quote:Originally posted by bambambam
Thanks, but I still have one thing in mind.
It's a Remington Model 770.Expecting it to shoot is like sitting on an egg hoping for a gold nuget. BUT, stranger things have happened[:p]
It will be ok, just have faith, Remington rifles have good barrels, just don't get it red hot when testing!
I've seen several Remington rifles that would group better than the guy behind the trigger, especially the Magnums! Wear ear muffs and a sissy bag and quit shooting if you get flinchy!
You can place the sissy bag under your shirt bdfore leaving the house and no one will know you have it on![;)]0 -
quote:Originally posted by Okie743
quote:Originally posted by bambambam
Thanks, but I still have one thing in mind.
It's a Remington Model 770.Expecting it to shoot is like sitting on an egg hoping for a gold nuget. BUT, stranger things have happened[:p]
It will be ok, just have faith, Remington rifles have good barrels, just don't get it red hot when testing!
I've seen several Remington rifles that would group better than the guy behind the trigger, especially the Magnums! Wear ear muffs and a sissy bag and quit shooting if you get flinchy!
You can place the sissy bag under your shirt before leaving the house and no one will know you have it on![;)]0 -
That's the pleasure of having your own range. I can shoot when I want and blow up whatever I want[:0]
What's a sissy bag?
quote:Originally posted by Okie743
quote:Originally posted by Okie743
quote:Originally posted by bambambam
Thanks, but I still have one thing in mind.
It's a Remington Model 770.Expecting it to shoot is like sitting on an egg hoping for a gold nuget. BUT, stranger things have happened[:p]
It will be ok, just have faith, Remington rifles have good barrels, just don't get it red hot when testing!
I've seen several Remington rifles that would group better than the guy behind the trigger, especially the Magnums! Wear ear muffs and a sissy bag and quit shooting if you get flinchy!
You can place the sissy bag under your shirt before leaving the house and no one will know you have it on![;)]0
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