Home Forums Hunting & Shooting Custom Rifles & Wildcats 6mm CM freebore

Looks like saami is .183. What's a good length for a custom reamer to use with a variety of VLDs?

I'm currently working with the old 105 HP Hornady's & I can only run about 2.7 OAL in a factory chamber. I don't have any sleek VLDs to play with right now, but thinking they have more nose taper & the factory chamber will be fine then & allow more overall length. Or not?

I might be ordering a reamer soon & just lookin for thoughts on the matter.

I had a Krieger barrel put together on a Bighorn Origin in 6mm with a 7.5 twist. I opted to go with the SAAMI .183. With that said, I'm running 115 DTACs. When I measured the DTACs to the lands, this gave me an COAL of 2.830 and a BTO of 2.259. I'm planning on seating them to a COAL of 2.800 which should be about .030 off of the lands.

This may not be what you're looking for. However, it's a sample of one. I'll also run 108 ELDs which I haven't measured yet.

.183 works well for all bullets up to the long ELDs.

Josh at PVA has reamers up to .210 which he found has worked very well jumping bullets.

.183 will serve you well as a universal chamber.

Thanks guys, just what I tried to convey.

Thinking the older 105 Hornady has a longer bearing length & a fatter ogive that's confusing the situation.

After I ask I realized I may have enough Sinclair & Stoney point gauges to clear things up. Just lacking a modified case in 6 CM. Backordered everywhere.

L65,

"PVA" is going over mine & Googles head, not familiar with them here.

??

Patriot Valley Arms

Don’t [bleep] it up. Go Saami with this one.

saami .183 will serve you well

I shot this 10 shot group at 220 yards with 108s last week. I have 2 6 Creedmoor rifles using the EABCO prefit barrels.


https://www.eabco.net/EABCO-Accuracy-Barrel-fits-Remington-700-6mm-Creedmoor-18-Blue_p_16221.html

Here you go. I just ordered one in the last week from EBay:

https://www.ebay.com/itm/233393078298?epid=2148446829&hash=item36574fc01a:g:kh0AAOSwcYVdwHOg

Thanks again guys, gettin it all together now, will be able to learn from a factory chamber I have, & go from there.

I thought the saami should be all that's needed, but the first bullet I tried confused me on throat length. I have a bullet comparator just no other good bullets to play with at this time.

.199 eliminates some pressure spikes

Go SAAMI as there was a fair amount of research put in to choosing that length. If for some reason you felt like you needed more it could be re-cut a lot easier than shortening a too long throat. It also gives more room to chase the lands if your so inclined.

Don't base the throat on a discontinued bullet as the newer VLDs have sharper ogives that require less free bore.

On my most recent 6 CM barrel I went with a shorter-than-SAAMI throat. I found in a couple of barrels that a SAAMI throat meant that I couldn't reach the lands with the 108 ELD or 115 DTAC unless the bullet shank was only held by half of the neck. On this latest barrel I had it throated so that I could hit lands with the bullet shank on the 115 DTAC just above the neck/shoulder junction. The SAAMI throat was fine if you wanted to jump ~0.050".

Easier to lengthen a short throat than to shorten one after the fact.

As an aside - how many rounds are you guys getting from a 6mm CM barrel? I'm nowhere near replacing the barrel on my Ruger Precision Rifle, but the day will come.

With that rifle I have to fit to the magazine and chamber both. So far I've just duplicated the length of the 108 gr Hornady factory ammo, and have only used the 108 gr Hornady ELD match bullets. Have used both Superformance and H4350 with good results.

So - when I need to re-barrel, it looks like the consensus is the SAAMI throat?

Thanks, Guy

Go SAAMI... I’m finding the 108s act way more consistent for me seated .065-.080 off.

Pulled my last 6 CM barrel off last week with 1440 rounds on it. Velocity hasn’t fallen off and still shoots sub MOA, but getting an occasional, unexplainable flyer. Started the new barrel (after 100 rounds) with the same powder charge and seating depth and it hammers.

Well, after some procrastination, searching for one, and shortage hold ups with shipping, my 6CM modified case came in yesterday.

Thought the Hornady 105 BTHP I was working with had a really short ogive for me to have to seat as deep as needed.

Nope, I just got Ruger bit.... AGAIN. My new #%^&*%$##$ rifle ain't got a fugging throat! I suppose yet another makes it's required trip back to the factory. Rugers sure some home sick sons a bucks.

A SAAMI, or .183" throat seems like it will be fine after all. Assuming my new factory rifle would be SAAMI, but assuming made an ass out of me again, or was it the rifle.

I had JGS make me a reamer with a .163 FB and 110 SMKs will touch the lands and still fit in AI mags. That being said, I'm finding a lot of LR 6mm bullets respond well to some jump, so .183 may be the best option.

I run the 115's in a 6 XC which is shorter than a Creed, plus the wyatt's mag box adding another .120. This is the fly in the ointment, and it also leads one to think that a long action is better for a creed vs a short action. Many of the vld type of bullets like to be up touching, jamming, or just barely off the lands. In the above, 800 rounds from now, the bullet will be jumping a LONG ways...loss of accuracy.

I use .123 freebore on my 6.5x47 Lapua which is a tad shorter than a std 6.5 Creed, had a wyatts mag box installed in my rem Short action 700 which gave me another .120 in oal I shoot the 123-130g bullets in my 6.5x47 Lapua till the leade grows from wear, then will go with 140g berger, eld's.

Installing a Wyatt's mag box in a Short Action Rem 700 for a creed is a smart move. The Wyatt's may fit in the Big horn Origin.

Hard lessons learned with many $ wasted chasing accuracy on cartridges too long for their magazine, soured me on "Short Actions" unless the Cartridge Base To Ogive works with room left to chase the lands as the leade grows. I am looking for accuracy in the extremes, and when my barrel starts shooting 3/4 MOA, I consider the barrel shot out or needing a "set back".

The 6 Creed has a pressure spike with shorter freebores, and mine has .210 freebore and would probably be better with .230 from some guys say...problem solved, and mine is on a Remington long action. The use of the long action means that I will get much more than 1200 rounds out of a barrel.

Short action vs long action is about 6 Oz!

Hey Keith, you use a factory follower with the Wyatt extended box?

'I'm seeing a lot of folks are talking the use of the newer Wyatt extended follower for best results.