oal and accuracy in a T/C Contender

[willymc]

Almost ready to make up my 1st .35 Remington loads for my T/C Contender single shot. You folks at THR have been a huge help. I’ll be loading a Speer 180gr. Hot Core flat nose over H335. I’ll be starting with 34.5 grains of powder and working up in .5 grain increments to see what velocity gives me the tightest groups with this bullet at 50 - 75 yards. My last question, at least I hope it’s my last, is concerning oal. I made up a dummy round and found an overall length of 2.522” just touches the lands. The minimum oal, per my Lee 2nd edition, is 2.47” for this bullet and powder combination. This bullet has a cannelure, but I won’t be crimping these. Seating the bullet to where the case mouth is just below the cannelure, I have an oal of 2.50”. This gives me .26” of bullet, below the cannelure, held by neck tension. The 2.50” oal appears, to me at least, to be a fair compromise between maximum and minimum oal. Will increasing or decreasing oal from this point make a big difference in accuracy? I’m not looking for benchrest accuracy at long distances.

 

[k4swb]

You never know about seating depth until you try different seating.
I never look at seating depths in manuals, just use my guns chambers and magazines where applicable.
In my TCs I have found that right off the lands always works best for me.

Tinkering, part of the fun!

 

[willymc]

k4swb, How far is "right off the lands" for you, .01", .005", .002" ?

 

[k4swb]

k4swb, How far is "right off the lands" for you, .01", .005", .002" ?

I'll start at .001" and go back from there. Usually what I do is make sure that every round stays off the lands when closing the action. Some die sets I can maintain .001" and some need to be slightly more because I can't maintain that to +/-.000" with some of my bullet/die/press combinations.

Usually in my guns somewhere less than .010".

I have a Savage model 11 in .308 Winchester that I can't seat certain bullets within less than .100" and they fit the magazine. They don't shoot well at that seating but loading them to .002" and single feeding them they shoot really well. I don't load those for hunting.

Consistence is what you're after. A consistent .003" would be better than one at .001" and then one at .003" and another at .005" and then one up into the lands.

I do whatever works.
With Wilson hand dies and an arbor press .001" is fairly easy. With a 7/8"X14 press and dies not so much.

 

[Dthunter]

Good luck with your loading. I am presently working on a load for my 6TCU.
My 24"barrel likes the 80-85 grain weight range. It will print groups into .75" or less.

I am trying to develop a load for Bergers VLD style bullets. So far the 95's are not working so well. I dont think they are stabilizing.

I plan to try the 88 grain VLD flat based, Varmint bullet.
If I can get a consistant 1/2-3/4" load at 100, this will pave the way for me
To shoot targets out past 500yds. I would like to see if I could reach 800+.

Boy would that be fun! Ringging steel plates out there! Cheap fun!

 

[Kernel]

I load my Contender carbine barrel in 7-30 Waters to 2.815". Factory ammo, I suppose, having never seen any, would be around 2.520". Besides better accuracy, another plus to the longer OAL is it creates more volume in the case for powder. In my case, about 10% more powder (around 4 grains). That equates to about a 5% increase in velocity, with NO INCREASE IN PRESSURE. Sometimes there is such a thing as a free lunch. Something else to keep in mind as you work up loads.

 

[willymc]

Good point. I'll keep that in mind as I approach maximum loads.