Author Topic: Omega fouling (Read 1135 times)

AndyHass · « **on:** June 20, 2004, 07:28:06 AM »

Finally got out to break in my new thumbhole Omega. When I went to swab between shots, I found that the last 3-4 inches at the breech had a huge amount of fouling...not just the usual "crud ring" I was used to with my old Traditions Lightning. This was a solid slug around the barrel for 3-4 inches.
After much frustration, I finally found that if I went down until I hit it, then removed the patch and scraped off the thick layer of fouling on it, I could usually work it down to the breech in 6-8 strokes...though sometimes I still had to flip it over. Any more agressive and I ended up fighting a stuck range rod. Has anyone else experienced this?
My old gun had more or less continuous fouling with a small crud ring. This one has little fouling in the top 20 inches and a huge amount at the bottom. This makes me think...could the Omega burn much more of the powder in the first few inches, creating a bigger pressure spike? While my Traditions shot many weights of soft lead Precision Rifle bullets well, I tried 4 different ones in this gun and the best was 2.25" with the 220gr DC and only 80 grains. However 200 grain SSTs touched each other with 110 grains. Could a bigger pressure spike in the breech be deforming the back of the lead bullets as they experience more acceleration? Just a thought, no idea how to test it easily.
I'm also wondering if a small rifle primer conversion might ease the breech fouling?
Overall T/C gets an A+ for accuracy. I only shot two real groups with the most accurate load (110 grains FFg +200 SST) and both were under an inch out of a new barrel. The thumbhole stock is NICE. :grin:

Omega · « **Reply #1 on:** June 20, 2004, 12:14:54 PM »

Hi Andy,
What powder are you shooting and how much? I used to have a powder ring in my Omega's after 3, 4 shots with 150 grains of Pyro. After I changed to the #3 breech plug this disappeared. I've never had any luck with DC bullets at 1800 fps or above. I believe that the obteration of the soft lead launching at these speeds drastically affects accuracy and also radically changes the shape and BC of the bullet.

big6x6 · « **Reply #2 on:** June 20, 2004, 01:09:14 PM »

I've always gotten fowling when using more than 80-90gr of 777 in my Omegas. I just spit-patch good and ignore it!

The 200gr SST/Shockwaves shoot really good in my .50 Omega and my .50 Disc Elite. I'm going to be using those this fall.

AndyHass · « **Reply #3 on:** June 20, 2004, 01:51:32 PM »

Thanks Omega and Chuck,
There is more than one breech plug sold for this gun? Interesting. Though I think if I change I'll go with the rifle primer conversion. .25 cartridges are a lot easier to handle with cold hands and get out than the 209s. I have never really liked dealing with them.
I was using anywhere from 80 to 120 grains of FFg 777. The fouling didn't seem much different between these charges.
With my Traditions I had good luck with the PR bullets up to 2000 fps. I didn't have a chrony out but I am told that out of that barrel 80 grains and a 220 bullet give about 1800 fps...and that was the ONLY place I got any accuracy with them.
Yes, I was really impressed with the .200 SST. Usually having shots touching is a rarity, but it does not appear to be the case with this bullet and gun. I will get some velocities next week hopefully, and see what happens above 110 grains.

big6x6 · « **Reply #4 on:** June 20, 2004, 03:52:51 PM »

Andy,

" I didn't have a chrony out but I am told that out of that barrel 80 grains and a 220 bullet give about 1800 fps"

Shooting from my Disc Extreme .50(26" barrel) 220gr D/C clock an average of 1805fps loaded with 90gr fffg 777. Your estimate is close but maybe a little optimistic.

Wolfhound · « **Reply #5 on:** June 21, 2004, 02:40:16 AM »

Andy,
You should have the latest plug in your Omega now. I make it a policy to have a spare breech plug on hand and bought the newest plug for the Omega. It's the exact same one that is already in my Omega (Thumbhole like yours). It's got a very deep well in the face of the plug. Since the Fluted/Thumbhole model is the latest offering, it makes sense that they put their newest style plug in them.

That said, I do get some crud in mine, but a quick swab and it's a non issue.

AndyHass · « **Reply #6 on:** June 21, 2004, 04:38:08 AM »

Yes, it's a very deep-well plug. I might find a smaller diameter jag or grind one down to make it easier to pull the fouling out.

Vapour · « **Reply #7 on:** June 21, 2004, 05:11:40 AM »

In my Encore 209X50 90 grains of FFFg 777 and a 220 grain dead center gives 1875 fps +- 25 fps N=6. This was with a beta master chrony.

RandyWakeman · « **Reply #8 on:** June 22, 2004, 12:11:37 AM »

Quote from: Omega

I've never had any luck with DC bullets at 1800 fps or above. I believe that the obteration of the soft lead launching at these speeds drastically affects accuracy and also radically changes the shape and BC of the bullet.

Omega, you'll find it difficult to dramatically change the shape of the bullet-- as there is a barrel in the way. There is a reason for the shorter "step base" of the .40 and .44 Dead Centers-- which is prevent column collapse at the base, lengthen the bullet, and get the bullet out of the sabot quickly. The full boat-tail .45 caliber versions have supported bases (via black MMP sabots) to perform the same function. They are all good in Illinois to 2150 or so, keeping 1/2 MOA-- though Del Ramsey has found 2200 - 2250 fps to be problem-free, Cecil going to 2350 fps or so. The continous ogive presents very little frontal area and resultant nose pressure in flight; the obturation possible during initial set-back is only a couple of thousandths.

Omega · « **Reply #9 on:** June 22, 2004, 01:57:10 AM »

Hey Randy,
How was bear hunting? I think you know what I'm talking about as you've seen the sabots. Even though all the manufacturers involved shrug their shoulders claiming not to understand what occurred and accusing me of using smokeless powder ( real class I might add) none of them would step forward. There are plenty of people in the industry who do understand the phenomena and the pear shaped projectile caused by the obturation sure explains the low BC's Chuck reported.
What ever, I know your answer will be to defend all your favorites and that is no crime we all do the same. The fellow had a question and I had one answer for it and you another. Arguing isn't going to change that.

I'm off to the airport, flying to Tin Cup Lodge in the Yukon today to pay some bills catching giant lake trout!

My life sucks! Not!! :eek:

RandyWakeman · « **Reply #10 on:** June 22, 2004, 02:26:24 AM »

Quote from: Omega

Hey Randy,
How was bear hunting? I think you know what I'm talking about as you've seen the sabots. Even though all the manufacturers involved shrug their shoulders claiming not to understand what occurred and accusing me of using smokeless powder

The mosquito population is very impressive. Rich, certainly I've not "accused" you of anything-- and don't doubt your results, it is that my own have not been anything like it. Del made no wild claims against you, did he? Very hard to diagnose a ripped orange sabot without the barrel it came from.

I've had excellent results in Encores, Knights, and Savages at higher velocities-- with the Savage due to smokeless ( I dood it) and the 1:24 twist likely being a bit more demanding ride than the others, but still no problems. Throwing bullets into the same hole via a 10ML-II at 2080 - 2140 fps seems very unlikely to me with "wildly" distorted bullets. All I can comment on is what I've seen and experienced first hand. Happy to accept your observations, I'll share mine. If this was always the case, who would bother shooting them? I certainly would not. :shock:

AndyHass · « **Reply #11 on:** June 22, 2004, 04:31:21 AM »

Randy,
Do you have any experience with DCs out of Omegas? (I know you do with the Encore). Among my shooting group, we have little luck with them even on reduced charges in these guns. With my Omega, I shot the 195 grain .357 at 80-100 grains, with 4-6 inch groups. The 220 .40 was 2.25" at 80 grains and 5 inches at 100, and I don't consider 2.25" satisfactory. I know velocity alone is not the issue at these charges as I shot them out of my Traditions fine to 2000 fps. I am going to try the 240s before I give up on DC with this gun, but I would really like to know why it won't seem to shoot them. Guns are different, but with similar twist I'd think there would be a sweet spot SOMEWHERE.
I like shooting flat...and so far I appear to have .75 MOA with the 200 SST at 110 grains. I think I can beat that with a DC if I can get them to group.

RandyWakeman · « **Reply #12 on:** June 22, 2004, 09:55:48 AM »

No, had the best luck with just 295 gr. Powerbelts. Wolfhound has been carving them up with 250 gr. Shockwaves, and Chuck Hill uses 87 of the last 49 bullet types he has gotten his hands on. :shock: