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CT's, mashed tips and moly
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So still trying to get 2800 out of 180's from my "06 AI and 22" tube. I bought some of the CT Partition Golds and started to play with them. I am WELL over listed max loads and still seeing no scary pressure signs and velocities are in the low 27's. A few questions...

1) Having loaded only Ballistic tips and X's so far, how does one standardize seating depth with the generally deformed tips of the Partition bullets? You get your chamber length off the ogive but then seat off the unpredictable tip.

2) Moly. These bullets are moly coated. This apparently drastically affects pressures but is there some rule of thumb for load development? WQhat is this stuff doing to my bore? Cleaning? I did search past posts with out finding clear answers.

3) What's the standard velocity reduction per inch of barrell removed? I'm trying to evaluate my loads compared to factory. This gun is consistantly off by up to 150 fps. I have others that meet or exceed listed velocities even with shorter tubes than those used for the test data.

As always, thanks to all for taking the time to further enable my developing addiction.
 
Posts: 767 | Location: Seeley Lake Montana | Registered: 17 April 2002Reply With Quote
<BC hunter>
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I am sorry I cant answer your question about the moly use, although I have heard it can increase velocitys, with regular use. ie; once the barrel is coated.
As far as the tips on the Nos partitions, I dont think you have much to worry about. The bullet seating die, will bypass the tip by a slight amount, and actually contact the ogive of the bullet. Much like when you chamber a round in your rifle, the tip is clear of the barrel, although it may be slightly IN the barrel. The trick is to find out what your clearence to the ogive, not the tip of the bullet. Every bullet has a slightly different ogive, so you will have to pre-determine, each cartridges oal for your gun, then seat the bullet slightly deeper,as to get the recommended clearence.
 
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Snowcat,

I had the same problem with FMJ-soft points - couldn't accurately measure OAL becasue the tips were all banged-up. What I did was find a PRISTINE bullet with the point fully intact and seated it to the proper OAL. Then I set-up a gauge to measure on the ogive - the same spot every time. Knowing now what a perfect tipped bullet gave me in OAL and what it measured at the exact same spot on the ogive allowed me to accuratly set bullet depth on bullets with a less than perfect tip.

I made my gauge, but Sinclair makes them. Available through Midsouth, Midway, etc., for an $25 for a set.

Hope this helps -
Dino
 
Posts: 243 | Location: Northeast OH | Registered: 03 January 2002Reply With Quote
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Picture of Rob1SG
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I use a Sinclair Intl. comparator to measure OAL to the ogive. This way you can get the proper length with any bullet because you are not measuring from the tip. Stoney Point also makes one.Take your pick.
Moly has been known to rust the bore if left in to long as it will attract moisture from the air.
 
Posts: 1111 | Location: Edmond,OK | Registered: 14 March 2001Reply With Quote
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quote:
Originally posted by snowcat:
So still trying to get 2800 out of 180's from my "06 AI and 22" tube. ...I am WELL over listed max loads and still seeing no scary pressure signs and velocities are in the low 27's. A few questions...

1) Having loaded only Ballistic tips and X's so far, how does one standardize seating depth with the generally deformed tips of the Partition bullets? You get your chamber length off the ogive but then seat off the unpredictable tip.

2) Moly. These bullets are moly coated. This apparently drastically affects pressures but is there some rule of thumb for load development? WQhat is this stuff doing to my bore? Cleaning? I did search past posts with out finding clear answers.

3) What's the standard velocity reduction per inch of barrell removed? I'm trying to evaluate my loads compared to factory. This gun is consistantly off by up to 150 fps. I have others that meet or exceed listed velocities even with shorter tubes than those used for the test data.

As always, thanks to all for taking the time to further enable my developing addiction.

Hey snowcat, First off, let me say Moly Coated bullets can achieve higer Velocities at the same "Pressure" as Non-Coated bullets. But, to pick an arbitrary Velocity out of the air and attempt to get there is very dangerous.

Let me suggest you load to a SAFE MAX(aka watching the Pressure Indicators and ignoring the Velocity). Then just accept whatever Velocity you happen to end up with. If you want more Velocity, get a larger case or a longer barrel.

Overloading is a serious error. It creates "Metal Fatigue" in the Bolt/Receiver that simply can not be detected without special test equipment and chemicals. It shortens case life. And it indicates to everyone that you just do not understand how potentially dangerous an overload actually is.

Your #1. 1a) Pick any bullet out of a box and determine the Overall Cartridge Length(OCL) for that specific "Set-Up Bullet" to just Kiss-the-Lands. Use any method you are comfortable with. I use the old Flat Tip Jag in a Cleaning Rod Method.

1b) Put an empty case in the Press Shellholder and raise the Ram.(I trim all my cases, so they are exactly alike from shot to shot.) Screw your Seating Die into the Press until it touches the Casemouth. Back off the Seating Die a turn or so and secure the Lock Ring/Nut around the Sizing Die body with the Jam Set-Screw.

1c) Put the Set-Up Bullet in the Casemouth and ease the Seating Stem in until the OCL is the same as you originally measured in the firearm.

NOTE: Here is where the trick comes in.

1d) Return the case with the Set-Up Bullet at the correct OCL to the Shellholder and raise the Ram. Tighten the Seating Stem Jam Nut.

1e)Remove the Seating Die from the Press and with a 0.001" capable Caliper, measure the Overall(Seating) Die Length(ODL) and write that on the Bullet Box.

For example lets say your OCL was 2.775" and your ODL ended up being 3.875". Now if you want the Bullets from that specific box Seated 0.025" Off-the-Lands, you set the Seating Die to 3.850" ODL, screw it in the Press and begin Seating Bullets.

No need for any special tools and it is very accurate.

NOTE: It is VERY IMPORTANT to re-do this each time you open a new box of Bullets.

Due to Throat Errosion and Manufacturing tolerances, the ODL will vary slightly from box to box.

One last thing on this. Lets say you do this on a box of Bullets(we will pick 165gr Partitions), determine what the ODL is and shoot a few. Then lets say you practice over the Summer with 165gr Rem PSPs(to hold the cost down) and you run 300 bullets through the rifle. Then, re-do the ODL on the Partitions as if they were a new box to compensate for Throat Errosion.

2a) Moly is great stuff. I use it in every centerfire rifle I have. ALWAYS clean the rifle after you shoot it and leave a light coat of either oil or grease in the Bore. Just clean it as you normally would with one of the newer outstanding Bore Cleaners available today. Then grease a patch and run it through a couple of times. Finish with a clean patch to remove any excess lube.

2b)"Rob1SG" is correct that Bores can rust(and end up pitting) with Moly in them. Same is true for any Bore that has been shot and not cleaned/greased whether or not Moly is used. So, always clean/grease as soon as you get home after shooting, or just don't shoot the firearm. (I even clean mine at the Range.)

3a) There are Rules of Thumb, but there are no hard and fast exact numbers for this. Most folks use 25-28fps for 30-06 class cartridges. I use 1% of the Velocity as shown for a specific Load as shown in a good Component Manufacturers Manual for each inch.

Just "remember-to-forget" about the Velocity until you reach your SAFE MAX as indicated by your various Pressure Indicators and accept whatever Velocity it happens to be. Even 200fps doesn't amount to a pile of Impeached-Clinton on Game, but it could cause Metal Fatigue.

Best of luck to you. [Cool]
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
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Picture of Dave Jenkins
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Snowcat,
I suggest you go here for everything you wanted to know and more on Moly.
http://www.jarheadtop.com/
Look for a link to chapter 4
Those guys keep extremely detailed records. The claim that moly coating both your bullets and your barrel will pull your cold barrel zero (first shot) in with the rest of string was enough to convince me to try it. I recently checked with the author to see if his opinion has changed since a couple of years has gone by and he replied that he still follows those practices.
As far as the seating depth goes I utilize a Sinclair Comparator and the conventional wisdom is that generally speaking most 30 cals shoot best with the bullet just touching the rifiling. Back off your charges several grains though as pressure builds up quicker with the initial resistance.
Good Luck,
Dave
 
Posts: 569 | Location: VA, USA | Registered: 22 January 2002Reply With Quote
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