Cutting Edge Bullets-Sealtite Band

[seidersjoden]

I've always used 300 grain Berger OTM in my 338 Lapua, however, because California is going to a non lead state, I'm switching to copper. Because my barrel twist is too slow for the cutting edge 300g MTH I have to use the 277 grain MTAC. That being said when it comes to reloading I had my gun made with a really long throat so I can load the bullets out long and have more case capacity for powder. Is it OK if I load these bullets with the Sealtight band out past the neck? Or is it imperative that I load the band right at the end of the neck or inside of the neck?


Gun:
.338 Lapua
28" MTU Barrel
Long throat

Thanks

Joden

 

[benchracer]

Loading straight ammo is critical to making the MTH's work. For that reason, CE recommends against loading the STB further forward than the case mouth. Make sure you trim your cases to a uniform length and lightly chamfer the case mouths. Start your powder charge workup with the STB seated to touch the case mouth. You can seat deeper if you need to tune seating depth, but I doubt you will need to.

The conventional wisdom about loading close to the lands does not apply to these bullets.

BTW, I note that you plan to use the MTAC, rather than the MTH bullets. Do you understand that the MTAC's are not intended to expand?

 

[seidersjoden]

Thanks for the advice, yes I understand they are meant to not expand, for now MTAC, for target shooting, when I hunt, the MTH which are same size, BC, and weight.

So just to clarify, is it OK if I load the billet with the STB a couple hundred thousandths in front of the case beck instead of butted up to the neck like you recommended?

Or are you basically saying that regardless of the distance between the ogive and the lands to load the STB in front of the neck? Currently with the Berger 300g OTMs I do a .140 jump already so I'm not shy when it comes to jumping Bullets. Are you saying that these are similar to a berger highbred bullet where jumping it isn't a problem?

Thanks Joden

 

[benchracer]

[FONT=&quot]Here is part of some correspondence I had with one of the Cutting Edge tech guys when I first started using the MTH bullets:

For bullets like the MTH, have any patterns been noted during testing that suggest a tolerance or intolerance of bullet jump? How large should my increments be for testing seating depth?
[/FONT] [FONT=&quot]Normal starting point is the SealTite Band™ just above the end of the neck. From that point you can lengthen in .030 or .035" increments- normally not very sensitive at all to seating depth. OR you can seat the SealTite Band™ into the neck, up to one-half the length of the neck (or about .170" below case neck end).[/FONT][FONT=&quot] [/FONT]
[FONT=&quot]I worked up a great load for a 100% stock Steyr ProHunter in .270 Win. Using our 115 Copper Raptor (smooth body, and SealTite Band™ (STB) just like our MTH bullets) and H4350, I was repeatedly getting ½" groups at 100 yards. Then I had to do some ammo for a TV show in CA. My loads were at 3.400" OAL, but as I did not know if their rifle would accept it, so I deep seated the STB inside the neck, with a new OAL of 3.340". When I shot them I got this actual sub .250 group! So no… they are not "fussy" as far as seating depth.[/FONT]
[FONT=&quot] [/FONT]

 

[benchracer]

You may already be familiar with the instructions given on Cutting Edge's website, I am including them here for comparison purposes and to aid others who may read this thread:

Reloading Instructions

Thank you for your interest in shooting the latest technology in solid copper, match grade projectiles. Due to their unique design that includes a SealTite™band, or sealing band, there are some reloading practices that must be followed for optimum performance.
The copper used in the manufacturing of these projectiles is very soft and care must be taken in handling the bullets to ensure the SealTite™band or tip is not damaged. For this reason, they are packaged in a divided box. After the bullets are properly loaded into a case, the SealTite™band will be protected. Since these solid copper bullets rely solely on the hollow point being open for expansion, care must be taken to ensure the tip is not damaged as well. A paper clip can be used to open up the hole if it gets dented to ensure the bullet will expand properly by letting fluid enter the cavity which causes hydraulic pressure to split the tip.

We recommend to seat the bullets per note 4 instructions for load development and fine tuning can then be done with seating depth if accuracy is not satisfactory in this position.
Standard reloading procedures can be followed with a few exceptions:

1. Brass casings should be trimmed to standard trim length. Ensure the inside of the case mouth is chamfered a minimum of ¼ of the brass wall thickness preferably with a VLD chamfering tool. This will ensure the SealTite™ band is not sheared off if it needs to be installed further into the case than at the mouth of the case as well as preventing shaving of copper from the bullets body.
2. When seating the bullets, press the bullets into the case until the SealTite™ Band comes close to brass case mouth or use the pre-established COAL method (see 4 below). This will allow approximately .020-.025" jump of the SealTite™ Band into the chamber throat. If less of a jump is required, blacken the entire bullet and seat it shallower looking for marks.
3. Another method commonly used to seat bullets is to use an O.A.L gage to find where a bullet makes contact in a chamber. This method works well with the CEB bullets and is performed in the same manner as any bullet.
4. Since our Meplat is machined and consistent from bullet to bullet, COAL can be measured very accurately. Measuring the COAL is an easier way for most people (including us), to seat our bullets to proper depth. The distance from the tip to the boat tail side of the SealTite™ Band is given in the individual bullet descriptions which is called the bullet projection length. This dimension plus the brass length will put the SealTite™ Band in perfect position which will be close to the case mouth. This will typically allow .020-.025" jump of STB into the chamber throat. If the cartridge overall length (COAL) is too long to fit into your magazine, the bullet can be seated deeper which in turn will give the bullet more jump into the chamber throat. Do not in any case seat the bullets with the SealTite™ Band deeper than one half of the brass neck length. Otherwise the bullets will not be held securely enough to ensure they will not move if dropped on the tip or bumped.
5. Our bullets are capable of obtaining the same muzzle velocity as any other bullet of the same weight with similar pressure results. Our test results stated in the individual bullet descriptions are typically achieved using rifles with longer than standard barrels and are not typical results obtainable by using standard length barrels. Whatever your particular rifle is capable of producing speed wise with other bullets of a similar weight is what we recommend shooting our bullets at. As with any bullet, the maximum obtainable speed may or may not be the most accurate speed to shoot these bullets. This being said it is not uncommon with our "MAX" designated bullets to achieve higher velocities due to their short body length.

 

[benchracer]

Hopefully, the above information will be helpful in answering your questions. I like these bullets a lot and hope you find a combination that is to your liking. Good luck!

 

[seidersjoden]

Thanks a lot for the info Benchracer, good to know they aren't too sensitive to seating depth.


Joden