greetings,
I'm using a stock G20 Gen 5 and handloading for it. I load 200 gr. and 180 gr. XTP's as well as Montana Bullets 200 gr. WFN hard cast.  I recently decided to get some Bayou bullets 180 gr. Hi-Tec coated TC bullets. I'm using longshot with this bullet. Couldn't find any data in my manuals or online load apps for this bullet. I basically decided to take what information i could find online and my own testing results for 180 XTP bullets with longshot  backed off little over a full grain and half then worked up. I stopped at 8.2 grains longshot because its listed as max now in my information for jacketed bullets. i have no signs of pressure or anything at this load but stopped there because being the first time I've loaded cast or coated bullets and was bit nervous to go further without educated input.  I'm running 8.8-9.0 (over current book max) with 180 XTP so wondering if anyone here could tell me if they use this bullet and about what they feel is maximum load for them with this type bullet. I hand load for all my firearms but have never loaded any coated cast bullets before. Any guidance would be appreciated

Do you have any velocity data?  That is always my guide when working "off-book", which I do quite a bit since I buy a fair big of the "non-cannister" powders when I can get a great deal.

I would be looking for for 1200 fps as a hard max velocity with Longshot in a 200 grain bullet.  You will probably get there before you get to 8.2 grains as cast bullets, especially coated cast, tend to seal the bore better than jacketed bullets.

Lee Second Edition Revised 2016 shows 9.5 grains of longshot with a 180 grain jacketed bullet for 1287 fps and 34,600 psi.  Lee usually doesn't do their own testing and just compiles manufacturer data so I have no way to cross check the source and see if they have revised that load.  The velocity is in line with what I would expect from that charge weight, but the pressure is lower than I would expect.

9.0 is definitely spicy by book standards.  I would be very cautious with that load and would back it off if it was over 1300 fps.

Thank you,
I'm afraid I cant say what the velocity actually is because i lent my Chrono to my brother and he killed it with a perfect shot in the guts. Family! so until i can get another I'm just working off past experience and  with other loads and manufactures estimates. stinks but is what it is. I'm running 8.2 of longshot currently and was estimating it at about 1200 to 1225 also.
 

Thats 8.2 longshot with the coated 180 grain bullet. was guessing it at about 1200 to 1225.

I'm comfortable with my 200 grain AA#9 loads around 1175fps and have Chrono those.  The 180 gr. coated were the ones i was unexperienced with.
My older data showed 9.5 longshot as well but new data at Hodgdon and Hornady show max at 8.2 now for jacketed  which was why i stopped there especially with a cast coated bullet till im bit more educated and replace my Chrono.

I have used Longshot with several bullet weights and styles.  Some suspect that Longshot has been changed and was reason for the lower charge weights.
That being said here is where I am with my own 10mm firearms.
With 200 grain jacketed and hard cast Carnauba Red lube I stop at 9.2 - 9.4 grains of LS.
With 180 grain jacketed and hard cast Carnauba Red lube I stop at 9.6 grains of LS.

I will say the Alliant BE-86 has shown some great numbers even in these bullet weights.

Thank you so much The_Shadow,
I agree that when i noticed the change on longshot data to 8.2 from a few years back in older manuals i figured something was different now. I had tested my xtp loads awhile ago and had Chrono then but recently lost it before working up loads on the 180 grain coated cast bullets. I got to 8.2 and decided best to stop there even though i wasn't noticing anything for pressure signs till i can get a new chrono. Want to get somewhere between 1200 and 1300fps with good accuracy.
Thus i wasn't sure where i was so just stopped for now. felt like i could venture up around 9 grains to maybe 9.5 but because coated cast bullets were new to me i figured best stop for now,
  Ive heard BE-86 was a good choice from few people. Ive got bit over 8lbs of longshot and AA#9 so for now I'm going to stay with them. least till i get where i need to get more powder. I run my 200 grain bullets over A#9 with Mag primers and 180 grain bullets over longshot and standard primers. But again Being a newbie to cast coated bullets was concerned due to my ignorance and lack of experience with using them.