Folks

I have run into this before and thought it was just a matter of one brand's (SIERRA) 160-grain 7 mm bullet not fitting a particular rifle at the lands (Remington 700 BDL DM in .280 Rem.)

Now my .300 H&H with 200-grain SPEERs is doing the same thing as the .280 with 139-grain Hornadys.

That's two rifles now where despite a good cleaning regimen and consistent handloading have begun to "mark" the sides of bullets, making chambering difficult where it used to be easy.

My question is : ought I next to learn some specifics about adequately cleaning the throat area of these two rifles?

Thanx

BNagel

Different lot numbers on the bullets?

Different batch of reloads?

If either of the above, then re-set your seating die...

I use a product called IOSSO on a nylon brush to clean the "Carbon ring" from the throat on my BR rifle. You may want to try some Sweets 7.62 copper remover in your 280. Heavy copper fouling could be the culprit.

I use Sweet's for the whole barrel. Anything different about focusing on the throat? Maybe a bore mop and / or nylon brush larger than the actual caliber sized brush(es) normally used?

Don't think lot # has anything to do with my situation as the whole side of bullet(s) are tight, not just approaching the lands...


Which IOSSO -- paste bore cleaner? I have some J-B but haven't concentrated on the throat with it.

B

Yes, the white paste bore cleaner is what I use.

Thanx, guys.

I didn't have any IOSSO, but reread a few posts on cleaning and decided to use J-B bore paste. I got things straightened (cleaned) out by doing the following:

(a) using a nylon brush wrapped with a patch

(b) KROIL to wet the bore (already "cleaned")

(c) 100 strokes with J-B, focusing on throat
area but working the whole bore in as well

Looks shiny / no Cu left at the muzzle. And the
bullets chamber smoothly again in the .300 H&H.
Need a little more effort with the .280 Rem, but
chambering is smoother. Maybe I can revisit the 160-grain SIERRA's.

Barry